COP8SG Family 8-Bit CMOS ROM Based and OTP Microcontrollers with 8k to 32k Memory, Two Comparators and USART General Description The COP8SG Family ROM and OTP based microcontrollers are highly integrated COP8TM Feature core devices with 8k to 32k memory and advanced features including Analog comparators, and zero external components. These singlechip CMOS devices are suited for more complex applications requiring a full featured controller with larger memory, low EMI, two comparators, and a full-duplex USART. COP8SGx7 devices are 100% form-fit-function compatible OTP (One Time Programmable) versions for use in production or development of the COP8SGx5 ROM. Erasable windowed versions (Q3) are available for use with a range of COP8 software and hardware development tools. Family features include an 8-bit memory mapped architecture, 15 MHz CKI with 0.67 s instruction cycle, 14 interrupts, three multi-function 16-bit timer/counters with PWM, full duplex USART, MICROWIRE/PLUSTM, two analog comparators, two power saving HALT/IDLE modes, MIWU, idle timer, on-chip R/C oscillator, high current outputs, user selectable options (WATCHDOGTM, 4 clock/oscillator modes, power-on-reset), 2.7V to 5.5V operation, program code security, and 28/40/44 pin packages. Devices included in this datasheet are: Device Memory (bytes) RAM (bytes) I/O Pins Packages Temperature COP8SGE5 8k ROM 256 24/36/40 28 DIP/SOIC, 40 DIP, 44 PLCC/QFP/CSP -40 to +85C, -40 to +125C COP8SGG5 16k ROM 512 24/36/40 28 DIP/SOIC, 40 DIP, 44 PLCC/QFP/CSP -40 to +85C, -40 to +125C COP8SGH5 20k ROM 512 24/36/40 28 DIP/SOIC, 40 DIP, 44 PLCC/QFP/CSP -40 to +85C, -40 to +125C COP8SGK5 24k ROM 512 24/36/40 28 DIP/SOIC, 40 DIP, 44 PLCC/QFP/CSP -40 to +85C, -40 to +125C COP8SGR5 32k ROM 512 24/36/40 28 DIP/SOIC, 40 DIP, 44 PLCC/QFP/CSP -40 to +85C, -40 to +125C COP8SGE7 8k OTP EPROM 256 24/36/40 28 DIP/SOIC, 40 DIP, 44 PLCC/QFP/CSP -40 to +85C, -40 to +125C COP8SGR7 32k OTP EPROM 512 24/36/40 28 DIP/SOIC, 40 DIP, 44 PLCC/QFP/CSP -40 to +85C, -40 to +125C COP8SGR7-Q3 32k EPROM 512 24/36/40 28 DIP, 40 DIP, 44 PLCC Room Temp. Key Features n n n n n n n n n Low cost 8-bit microcontroller Quiet Design (low radiated emissions) Multi-Input Wakeup pins with optional interrupts (8 pins) Mask selectable clock options -- Crystal oscillator -- Crystal oscillator option with on-chip bias resistor -- External oscillator -- Internal R/C oscillator Internal Power-On-Reset -- user selectable WATCHDOG and Clock Monitor Logic -- user selectable Eight high current outputs 256 or 512 bytes on-board RAM 8k to 32k ROM or OTP EPROM with security feature CPU Features n Versatile easy to use instruction set n 0.67 s instruction cycle time n Fourteen multi-source vectored interrupts servicing -- External interrupt / Timers T0 -- T3 -- MICROWIRE/PLUS Serial Interface -- Multi-Input Wake Up -- Software Trap -- USART (2; 1 receive and 1 transmit) -- Default VIS (default interrupt) n 8-bit Stack Pointer SP (stack in RAM) n Two 8-bit Register Indirect Data Memory Pointers n True bit manipulation n BCD arithmetic instructions Peripheral Features n Multi-Input Wakeup Logic n Three 16-bit timers (T1 -- T3), each with two 16-bit registers supporting: -- Processor Independent PWM mode -- External Event Counter mode -- Input Capture mode COP8TM is a trademark of National Semiconductor Corporation. (c) 2001 National Semiconductor Corporation DS101317 www.national.com COP8SG Family, 8-Bit CMOS ROM Based and OTP Microcontrollers with 8k to 32k Memory, Two Comparators and USART October 2001 COP8SG Family Peripheral Features n n n n Fully Static CMOS Design (Continued) n Low current drain (typically < 4 A) n Two power saving modes: HALT and IDLE Idle Timer (T0) MICROWIRE/PLUS Serial Interface (SPI Compatible) Full Duplex USART Two Analog Comparators Temperature Range n -40C to +85C, -40C to +125C I/O Features Development Support n Software selectable I/O options (TRI-STATE (R) Output,Push-Pull Output, Weak Pull-Up Input, and High Impedance Input) n Schmitt trigger inputs on ports G and L n Eight high current outputs n Packages: 28 SO with 24 I/O pins, 40 DIP with 36 I/O pins, 44 PLCC, PQFP and CSP with 40 I/O pins n Windowed packages for DIP and PLCC n Real time emulation and debug tools available Block Diagram 10131744 FIGURE 1. COP8SGx Block Diagram www.national.com 2 1.1 ARCHITECTURE The COP8 family is based on a modified Harvard architecture, which allows data tables to be accessed directly from program memory. This is very important with modern microcontroller-based applications, since program memory is usually ROM or EPROM, while data memory is usually RAM. Consequently data tables need to be contained in non-volatile memory, so they are not lost when the microcontroller is powered down. In a modified Harvard architecture, instruction fetch and memory data transfers can be overlapped with a two stage pipeline, which allows the next instruction to be fetched from program memory while the current instruction is being executed using data memory. This is not possible with a Von Neumann single-address bus architecture. The COP8 family supports a software stack scheme that allows the user to incorporate many subroutine calls. This capability is important when using High Level Languages. With a hardware stack, the user is limited to a small fixed number of stack levels. JID: (Jump Indirect); Single byte instruction; decodes external events and jumps to corresponding service routines (analogous to "DO CASE" statements in higher level languages). LAID: (Load Accumulator-Indirect); Single byte look up table instruction provides efficient data path from the program memory to the CPU. This instruction can be used for table lookup and to read the entire program memory for checksum calculations. RETSK: (Return Skip); Single byte instruction allows return from subroutine and skips next instruction. Decision to branch can be made in the subroutine itself, saving code. AUTOINC/DEC: (Auto-Increment/Auto-Decrement); These instructions use the two memory pointers B and X to efficiently process a block of data (analogous to "FOR NEXT" in higher level languages). 1.2.3 Bit-Level Control Bit-level control over many of the microcontroller's I/O ports provides a flexible means to ease layout concerns and save board space. All members of the COP8 family provide the ability to set, reset and test any individual bit in the data memory address space, including memory-mapped I/O ports and associated registers. 1.2 INSTRUCTION SET In today's 8-bit microcontroller application arena cost/ performance, flexibility and time to market are several of the key issues that system designers face in attempting to build well-engineered products that compete in the marketplace. Many of these issues can be addressed through the manner in which a microcontroller's instruction set handles processing tasks. And that's why COP8 family offers a unique and code-efficient instruction set -- one that provides the flexibility, functionality, reduced costs and faster time to market that today's microcontroller based products require. Code efficiency is important because it enables designers to pack more on-chip functionality into less program memory space. Selecting a microcontroller with less program memory size translates into lower system costs, and the added security of knowing that more code can be packed into the available program memory space. 1.2.4 Register Set Three memory-mapped pointers handle register indirect addressing and software stack pointer functions. The memory data pointers allow the option of post-incrementing or postdecrementing with the data movement instructions (LOAD/ EXCHANGE). And 15 memory-maped registers allow designers to optimize the precise implementation of certain specific instructions. 1.3 EMI REDUCTION The COP8SGx5 family of devices incorporates circuitry that guards against electromagnetic interference -- an increasing problem in today's microcontroller board designs. National's patented EMI reduction technology offers low EMI clock circuitry, gradual turn-on output drivers (GTOs) and internal ICC smoothing filters, to help circumvent many of the EMI issues influencing embedded control designs. National has achieved 15 dB-20 dB reduction in EMI transmissions when designs have incorporated its patented EMI reducing circuitry. 1.2.1 Key Instruction Set Features The COP8 family incorporates a unique combination of instruction set features, which provide designers with optimum code efficiency and program memory utilization. Single Byte/Single Cycle Code Execution The efficiency is due to the fact that the majority of instructions are of the single byte variety, resulting in minimum program space. Because compact code does not occupy a substantial amount of program memory space, designers can integrate additional features and functionality into the microcontroller program memory space. Also, the majority instructions executed by the device are single cycle, resulting in minimum program execution time. In fact, 77% of the instructions are single byte single cycle, providing greater code and I/O efficiency, and faster code execution. 1.4 PACKAGING/PIN EFFICIENCY Real estate and board configuration considerations demand maximum space and pin efficiency, particularly given today's high integration and small product form factors. Microcontroller users try to avoid using large packages to get the I/O needed. Large packages take valuable board space and increases device cost, two trade-offs that microcontroller designs can ill afford. The COP8 family offers a wide range of packages and do not waste pins: up to 90.9% (or 40 pins in the 44-pin package) are devoted to useful I/O. 1.2.2 Many Single-Byte, Multifunction Instructions The COP8 instruction set utilizes many single-byte, multifunction instructions. This enables a single instruction to accomplish multiple functions, such as DRSZ, DCOR, JID, LD (Load) and X (Exchange) instructions with post- 3 www.national.com COP8SG Family incrementing and post-decrementing, to name just a few examples. In many cases, the instruction set can simultaneously execute as many as three functions with the same single-byte instruction. 1.0 Device Description COP8SG Family Connection Diagrams 10131704 Top View Order Number COP8SGXY28M8 See NS Package Number M28B Order Number COP8SGXY28N8 See NS Package Number N28B Order Number COP8SGR728Q3 See NS Package Number D28JQ 10131753 Top View Order Number COP8SGR7HLQ8 See NS Package Number LQA44A 10131705 Top View Order Number COP8SGXY40N8 See NS Package Number N40A Order Number COP8SGR5740Q3 See NS Package Number D40KQ 10131706 10131743 Top View Order Number COP8SGXY44V8 See NS Package Number V44A Order Number COP8SGR744J3 See NS Package Number EL44C Top View Order Number COP8SGXYVEJ8 See NS Package Number VEJ44A Note 1: X = E for 8k, G for 16k, H for 20k, K for 24k, R for 32k Y = 5 for ROM, 7 for OTP www.national.com 4 Port Type Alt. Fun 28-Pin SO 40-Pin DIP 44-Pin PLCC 44-Pin PQFP 44-Pin CSP L0 I/O MIWU 11 17 17 11 12 L1 I/O MIWU or CKX 12 18 18 12 13 L2 I/O MIWU or TDX 13 19 19 13 14 L3 I/O MIWU or RDX 14 20 20 14 15 L4 I/O MIWU or T2A 15 21 25 19 20 L5 I/O MIWU or T2B 16 22 26 20 21 L6 I/O MIWU or T3A 17 23 27 21 22 L7 I/O MIWU or T3B 18 24 28 22 23 G0 I/O INT 25 35 39 33 34 G1 I/O WDOUT* 26 36 40 34 35 G2 I/O T1B 27 37 41 35 36 G3 I/O T1A 28 38 42 36 37 G4 I/O SO 1 3 3 41 42 G5 I/O SK 2 4 4 42 43 G6 I SI 3 5 5 43 44 G7 I CKO 4 6 6 44 1 D0 O 19 25 29 23 24 D1 O 20 26 30 24 25 D2 O 21 27 31 25 26 D3 O 22 28 32 26 27 D4 O 29 33 27 28 D5 O 30 34 28 29 D6 O 31 35 29 30 D7 O 32 36 30 31 F0 I/O 7 9 9 3 4 F1 I/O COMP1IN- 8 10 10 4 5 F2 I/O COMP1IN+ 9 11 11 5 6 F3 I/O COMP1OUT 10 12 12 6 7 F4 I/O COMP2IN- 13 13 7 8 F5 I/O COMP2IN+ 14 14 8 9 F6 I/O COMP2OUT 15 15 9 10 F7 I/O 16 16 10 11 C0 I/O 39 43 37 38 C1 I/O 40 44 38 39 C2 I/O 1 1 39 40 C3 I/O 2 2 40 41 C4 I/O 21 15 16 C5 I/O 22 16 17 C6 I/O 23 17 18 C7 I/O 24 18 19 VCC GND 6 8 8 2 3 32 23 33 37 31 CKI I 5 7 7 1 2 RESET I 24 34 38 32 33 * G1 operation as WDOUT is controlled by ECON bit 2. 5 www.national.com COP8SG Family Pinouts for 28 -, 40- and 44-Pin Packages COP8SG Family 2.1 Ordering Information 10131708 FIGURE 2. Part Numbering Scheme www.national.com 6 Absolute Maximum Ratings Total Current out of GND Pin (Sink) (Note 2) Supply Voltage (VCC) Voltage at Any Pin -65C to +140C ESD Protection Level 7V 2kV (Human Body Model) Note 2: Absolute maximum ratings indicate limits beyond which damage to the device may occur. DC and AC electrical specifications are not ensured when operating the device at absolute maximum ratings. -0.3V to VCC +0.3V Total Current into VCC Pin (Source) 110 mA Storage Temperature Range If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. COP8SG Family 3.0 Electrical Characteristics 100 mA DC Electrical Characteristics -40C TA +85C unless otherwise specified. Parameter Conditions Operating Voltage Min Typ 2.7 Max Units 5.5 V 6 Power Supply Rise Time 10 50 x 10 ns VCC Start Voltage to Guarantee POR 0 0.25 V 0.1 Vcc V Power Supply Ripple (Note 4) Peak-to-Peak Supply Current (Note 5) CKI = 15 MHz VCC = 5.5V, tC = 0.67 s 9.0 mA CKI = 10 MHz VCC = 5.5V, tC = 1 s 6.0 mA CKI = 4 MHz VCC = 4.5V, tC = 2.5 s 2.1 mA 10 A HALT Current (Note 6) <4 VCC = 5.5V, CKI = 0 MHz IDLE Current (Note 5) CKI = 15 MHz VCC = 5.5V, tC = 0.67 s 2.25 mA CKI = 10 MHz VCC = 5.5V, tC = 1 s 1.5 mA CKI = 4 MHz VCC = 4.5V, tC = 2.5 s 0.8 mA Input Levels (VIH, VIL) RESET Logic High 0.8 Vcc V Logic Low 0.2 Vcc V CKI, All Other Inputs Logic High 0.7 Vcc V Logic Low Internal Bias Resistor for the Crystal/Resonator Oscillator CKI Resistance to VCC or GND when R/C Oscillator is selected VCC = 5.5V 0.2 Vcc V 0.5 1 2 M 5 8 11 k Hi-Z Input Leakage VCC = 5.5V -2 +2 A Input Pullup Current VCC = 5.5V, VIN = 0V -40 -250 A G and L Port Input Hysteresis VCC = 5.5V 0.25 Vcc 7 V www.national.com COP8SG Family DC Electrical Characteristics (Continued) -40C TA +85C unless otherwise specified. Parameter Conditions Min Typ Max Units Output Current Levels D Outputs Source Sink VCC = 4.5V, VOH = 3.3V -0.4 mA VCC = 2.7V, VOH = 1.8V -0.2 mA VCC = 4.5V, VOL = 1.0V 10 mA VCC = 2.7V, VOL = 0.4V 2 mA All Others Source (Weak Pull-Up Mode) Source (Push-Pull Mode) Sink (Push-Pull Mode) TRI-STATE Leakage VCC = 4.5V, VOH = 2.7V -10.0 -110 VCC = 2.7V, VOH = 1.8V -2.5 -33 VCC = 4.5V, VOH = 3.3V -0.4 mA VCC = 2.7V, VOH = 1.8V -0.2 mA VCC = 4.5V, VOL = 0.4V VCC = 2.7V, VOL = 0.4V 1.6 0.7 mA mA VCC = 5.5V -2 A A +2 A Allowable Sink Current per Pin (Note 9) D Outputs and L0 to L3 15 mA All Others 3 mA Maximum Input Current without Latchup (Note 7) Room Temp. 200 RAM Retention Voltage, Vr mA 2.0 V 12 s VCC Rise Time from a VCC 2.0V (Note 10) EPROM Data Retenton (Note 8), (Note 9) TA = 55C Input Capacitance (Note 9) 7 pF Load Capacitance on D2 (Note 9) 1000 pF > 29 years AC Electrical Characteristics -40C TA +85C unless otherwise specified. Parameter Conditions Min 4.5V VCC 5.5V 0.67 2.7V VCC 4.5V 2 Typ Max Units Instruction Cycle Time (tC) Crystal/Resonator, External R/C Oscillator (Internal) Frequency Variation (Note 9) External CKI Clock Duty Cycle (Note 9) s s 4.5V VCC 5.5V 2 4.5V VCC 5.5V 35 fr = Max 45 s % 55 % ns Rise Time (Note 9) fr = 10 MHz Ext Clock 8 Fall Time (Note 9) fr = 10 MHz Ext Clock 5 ns MICROWIRE Setup Time (tUWS) (Note 11) 20 ns MICROWIRE Hold Time (tUWH) (Note 11) 56 ns 220 MICROWIRE Output Propagation Delay (tUPD) (Note 11) ns Input Pulse Width (Note 9) Interrupt Input High Time 1 tC Interrupt Input Low Time 1 tC Timer 1, 2, 3, Input High Time 1 tC Timer 1 2, 3, Input Low Time 1 tC 1 s Reset Pulse Width Note 3: tC = Instruction cycle time. www.national.com 8 Note 4: Maximum rate of voltage change must be (Continued) < 0.5 V/ms. Note 5: Supply and IDLE currents are measured with CKI driven with a square wave Oscillator, External Oscillator, inputs connected to VCC and outputs driven low but not connected to a load. Note 6: The HALT mode will stop CKI from oscillating in the R/C and the Crystal configurations. In the R/C configuration, CKI is forced high internally. In the crystal or external configuration, CKI is TRI-STATE. Measurement of IDD HALT is done with device neither sourcing nor sinking current; with L. F, C, G0, and G2-G5 programmed as low outputs and not driving a load; all outputs programmed low and not driving a load; all inputs tied to VCC; clock monitor disabled. Parameter refers to HALT mode entered via setting bit 7 of the G Port data register. Note 7: Pins G6 and RESET are designed with a high voltage input network. These pins allow input voltages > VCC and the pins will have sink current to VCC when biased at voltages > VCC (the pins do not have source current when biased at a voltage below VCC). The effective resistance to VCC is 750 (typical). These two pins will not latch up. The voltage at the pins must be limited to < 14V. WARNING: Voltages in excess of 14V will cause damage to the pins. This warning excludes ESD transients. Note 8: National Semiconductor uses the High Temperature Storage Life (HTSL) test to evaluate the data retention capabilities of the EPROM memory cells used in our OTP microcontrollers. Qualification devices have been stressed at 150C for 1000 hours. Under these conditions, our EPROM cells exhibit data retention capabilities in excess of 29 years. This is based on an activation energy of 0.7eV derated to 55C. Note 9: Parameter characterized but not tested. Note 10: Rise times faster than the minimum specification may trigger an internal power-on-reset. Note 11: MICROWIRE Setup and Hold Times and Propagation Delays are referenced to the appropriate edge of the MICROWIRE clock. See and the MICROWIRE operation description. Comparators AC and DC Characteristics VCC = 5V, -40C TA +85C. Parameter Input Offset Voltage (Note 12) Conditions Min Typ 0.4V VIN VCC - 1.5V Input Common Mode Voltage Range 5 0.4 Max Units 15 mV VCC - 1.5 Voltage Gain 100 V dB Low Level Output Current VOL = 0.4V -1.6 mA High Level Output Current VOH = VCC - 0.4V 1.6 mA DC Supply Current per Comparator (When Enabled) Response Time (Note 13) 200 mV step input 100 mV Overdrive, 100 pF Load Comparator Enable Time(Note 14) 150 A 600 ns 600 ns Note 12: The comparator inputs are high impedance port inputs and, as such, input current is limited to port input leakage current. Note 13: Response time is measured from a step input to a valid logic level at the comparator output. software response time is dependent of instruction execution. Note 14: Comparator enable time is that delay time required between the end of the instruction cycle that enables the comparator and using the output of the comparator, either by hardware or by software. 10131709 FIGURE 3. MICROWIRE/PLUS Timing 9 www.national.com COP8SG Family AC Electrical Characteristics COP8SG Family Absolute Maximum Ratings (Note 2) Storage Temperature Range If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. Supply Voltage (VCC) Voltage at Any Pin ESD Protection Level 7V 100 mA Total Current out of GND Pin (Sink) 110 mA 2kV (Human Body Model) Note 15: Absolute maximum ratings indicate limits beyond which damage to the device may occur. DC and AC electrical specifications are not ensured when operating the device at absolute maximum ratings. -0.3V to VCC +0.3V Total Current into VCC Pin (Source) -65C to +140C DC Electrical Characteristics -40C TA +125C unless otherwise specified. Parameter Conditions Min Typ Max Units Operating Voltage 4.5 5.5 V Power Supply Rise Time 10 50 x 106 ns VCC Start Voltage to Guarantee POR Power Supply Ripple (Note 4) 0 Peak-to-Peak 0.25 V 0.1 Vcc V Supply Current (Note 5) CKI = 10 MHz VCC = 5.5V, tC = 1 s 6.0 mA CKI = 4 MHz VCC = 4.5V, tC = 2.5 s 2.1 mA 10 A HALT Current (Note 6) <4 VCC = 5.5V, CKI = 0 MHz IDLE Current (Note 5) CKI = 10 MHz VCC = 5.5V, tC = 1 s 1.5 mA CKI = 4 MHz VCC = 4.5V, tC = 2.5 s 0.8 mA Input Levels (VIH, VIL) RESET Logic High 0.8 Vcc V Logic Low 0.2 Vcc V CKI, All Other Inputs Logic High 0.7 Vcc V Logic Low Internal Bias Resistor for the Crystal/Resonator Oscillator CKI Resistance to VCC or GND when R/C Oscillator is selected VCC = 5.5V 0.2 Vcc V 0.5 1 2 M 5 8 11 k Hi-Z Input Leakage VCC = 5.5V -5 +5 A Input Pullup Current VCC = 5.5V, VIN = 0V -35 -400 A G and L Port Input Hysteresis VCC = 5.5V 0.25 Vcc V Output Current Levels D Outputs Source VCC = 4.5V, VOH = 3.3V -0.4 mA Sink VCC = 4.5V, VOL = 1.0V 9 mA All Others Source (Weak Pull-Up Mode) VCC = 4.5V, VOH = 2.7V -9 Source (Push-Pull Mode) VCC = 4.5V, VOH = 3.3V -0.4 VCC = 4.5V, VOL = 0.4V 1.4 VCC = 5.5V -5 Sink (Push-Pull Mode) TRI-STATE Leakage -140 A mA mA +5 A Allowable Sink Current per Pin (Note 9) D Outputs and L0 to L3 15 All Others www.national.com 3 10 15 mA 3 mA (Continued) -40C TA +125C unless otherwise specified. Parameter Maximum Input Current without Latchup (Note 7) Conditions Min Typ Room Temp. RAM Retention Voltage, Vr Max Units 200 mA 2.0 V 12 s VCC Rise Time from a VCC 2.0V (Note 10) EPROM Data Retenton (Note 8),(Note 9) TA = 55C Input Capacitance (Note 9) 7 pF Load Capacitance on D2 (Note 9) 1000 pF > 29 11 years www.national.com COP8SG Family DC Electrical Characteristics COP8SG Family AC Electrical Characteristics -40C TA +125C unless otherwise specified. Parameter Conditions Min Typ Max Units Instruction Cycle Time (tC) Crystal/Resonator, External 4.5V VCC 5.5V R/C Oscillator (Internal) 4.5V VCC 5.5V 2 4.5V VCC 5.5V 35 Frequency Variation (Note 9) External CKI Clock Duty Cycle (Note 9) fr = Max 1 s 45 s % 55 % ns Rise Time (Note 9) fr = 10 MHz Ext Clock 12 Fall Time (Note 9) fr = 10 MHz Ext Clock 8 ns MICROWIRE Setup Time (tUWS) (Note 11) 20 ns MICROWIRE Hold Time (tUWH) (Note 11) 56 ns 220 MICROWIRE Output Propagation Delay (tUPD) (Note 11) ns Input Pulse Width (Note 9) Interrupt Input High Time 1 tC Interrupt Input Low Time 1 tC Timer 1, 2, 3, Input High Time 1 tC Timer 1 2, 3, Input Low Time 1 tC 1 s Reset Pulse Width Comparators AC and DC Characteristics VCC = 5V, -40C TA +125C. Parameter Input Offset Voltage (Note 12) Conditions Min 0.4V VIN VCC - 1.5V Input Common Mode Voltage Range Typ Max Units 5 25 mV 0.4 Voltage Gain VCC - 1.5 100 V dB Low Level Output Current VOL = 0.4V -1.6 mA High Level Output Current VOH = VCC - 0.4V 1.6 mA DC Supply Current per Comparator (When Enabled) Response Time (Note 13) 200 mV step input 100 mV Overdrive, Comparator Enable Time www.national.com 12 150 A 600 ns 600 ns COP8SG Family Typical Performance Characteristics TA = 25C (unless otherwise specified) 10131749 10131750 10131751 10131752 13 www.national.com COP8SG Family dedicated WATCHDOG output with weak pullup if WATCHDOG feature is selected by the Mask Option register. The pin is a general purpose I/O if WATCHDOG feature is not selected. If WATCHDOG feature is selected, bit 1 of the Port G configuration and data register does not have any effect on Pin G1 setup. Pin G7 is either input or output depending on the oscillator option selected. With the crystal oscillator option selected, G7 serves as the dedicated output pin for the CKO clock output. With the internal R/C or the external oscillator option selected, G7 serves as a general purpose Hi-Z input pin and is also used to bring the device out of HALT mode with a low to high transition on G7. Since G6 is an input only pin and G7 is the dedicated CKO clock output pin (crystal clock option) or general purpose input (R/C or external clock option), the associated bits in the data and configuration registers for G6 and G7 are used for special purpose functions as outlined below. Reading the G6 and G7 data bits will return zeroes. Each device will be placed in the HALT mode by writing a "1" to bit 7 of the Port G Data Register. Similarly the device will be placed in the IDLE mode by writing a "1" to bit 6 of the Port G Data Register. Writing a "1" to bit 6 of the Port G Configuration Register enables the MICROWIRE/PLUS to operate with the alternate phase of the SK clock. The G7 configuration bit, if set high, enables the clock start up delay after HALT when the R/C clock configuration is used. 4.0 Pin Descriptions The COP8SGx I/O structure enables designers to reconfigure the microcontroller's I/O functions with a single instruction. Each individual I/O pin can be independently configured as output pin low, output high, input with high impedance or input with weak pull-up device. A typical example is the use of I/O pins as the keyboard matrix input lines. The input lines can be programmed with internal weak pull-ups so that the input lines read logic high when the keys are all open. With a key closure, the corresponding input line will read a logic zero since the weak pull-up can easily be overdriven. When the key is released, the internal weak pull-up will pull the input line back to logic high. This eliminates the need for external pull-up resistors. The high current options are available for driving LEDs, motors and speakers. This flexibility helps to ensure a cleaner design, with less external components and lower costs. Below is the general description of all available pins. VCC and GND are the power supply pins. All VCC and GND pins must be connected. CKI is the clock input. This can come from the Internal R/C oscillator, external, or a crystal oscillator (in conjunction with CKO). See Oscillator Description section. RESET is the master reset input. See Reset description section. Each device contains four bidirectional 8-bit I/O ports (C, G, L and F), where each individual bit may be independently configured as an input (Schmitt trigger inputs on ports L and G), output or TRI-STATE under program control. Three data memory address locations are allocated for each of these I/O ports. Each I/O port has two associated 8-bit memory mapped registers, the CONFIGURATION register and the output DATA register. A memory mapped address is also reserved for the input pins of each I/O port. (See the memory map for the various addresses associated with the I/O ports.) Figure 4 shows the I/O port configurations. The DATA and CONFIGURATION registers allow for each port bit to be individually configured under software control as shown below: CONFIGURATION Register DATA Register 0 0 Hi-Z Input 0 1 Input with Weak Pull-Up 1 0 Push-Pull Zero Output 1 1 Push-Pull One Output Config. Reg. CLKDLY HALT G6 Alternate SK IDLE Port G has the following alternate features: G7 CKO Oscillator dedicated output or general purpose input G6 SI (MICROWIRE Serial Data Input) G5 SK (MICROWIRE Serial Clock) G4 SO (MICROWIRE Serial Data Output) G3 T1A (Timer T1 I/O) G2 T1B (Timer T1 Capture Input) G1 WDOUT WATCHDOG and/or CLock Monitor if WATCHDOG enabled, otherwise it is a general purpose I/O G0 INTR (External Interrupt Input) Port Set-Up (TRI-STATE Output) Port C is an 8-bit I/O port. The 40-pin device does not have a full complement of Port C pins. The unavailable pins are not terminated. A read operation on these unterminated pins will return unpredictable values. The 28 pin device do not offer Port C. On this device, the associated Port C Data and Configuration registers should not be used. Port F is an 8-bit I/O port. The 28--pin device does not have a full complement of Port F pins. The unavailable pins are not terminated. A read operation on these unterminated pins will return unpredictable values. Port F1-F3 are used for Comparator 1. Port F4-F6 are used for Comparator 2. The Port F has the following alternate features: F6 COMP2OUT (Comparator 2 Output) F5 COMP2+IN (Comparator 2 Positive Input) F4 COMP2-IN (Comparator 2 Negative Input) F3 COMP1OUT (Comparator 1 Output) F2 COMP1+IN (Comparator 1 Positive Input) F1 COMP1-IN (Comparator 1 Negative Input) Port L is an 8-bit I/O port. All L-pins have Schmitt triggers on the inputs. Port L supports the Multi-Input Wake Up feature on all eight pins. Port L has the following alternate pin functions: L7 Multi-input Wakeup or T3B (Timer T3B Input) L6 Multi-input Wakeup or T3A (Timer T3A Input) L5 Multi-input Wakeup or T2B (Timer T2B Input) L4 Multi-input Wakeup or T2A (Timer T2A Input) L3 Multi-input Wakeup and/or RDX (USART Receive) L2 Multi-input Wakeup or TDX (USART Transmit) L1 Multi-input Wakeup and/or CKX (USART Clock) L0 Multi-input Wakeup Port G is an 8-bit port. Pin G0, G2-G5 are bi-directional I/O ports. Pin G6 is always a general purpose Hi-Z input. All pins have Schmitt Triggers on their inputs.Pin G1 serves as the www.national.com Data Reg. G7 14 COP8SG Family 4.0 Pin Descriptions (Continued) Note: For compatibility with existing software written for COP888xG devices and with existing Mask ROM devices, a read of the Port I input pins (address xxD7) will return the same data as reading the Port F input pins (address xx96). It is recommended new applications which will go to production with the COP8SGx use the Port F addresses. Note that compatible ROM devices contains the input only Port I instead of the bi-directional Port F. Port D is an 8-bit output port that is preset high when RESET goes low. The user can tie two or more D port outputs (except D2) together in order to get a higher drive. Note: Care must be exercised with the D2 pin operation. At RESET, the external loads on this pin must ensure that the output voltages stay above 0.7 VCC to prevent the chip from entering special modes. Also keep the external loading on D2 to less than 1000 pF. 10131712 FIGURE 5. I/O Port Configurations -- Output Mode 10131710 FIGURE 4. I/O Port Configurations 10131711 FIGURE 6. I/O Port Configurations -- Input Mode 15 www.national.com COP8SG Family dresses 0F0 to 0FE Hex. These registers can be loaded immediately, and also decremented and tested with the DRSZ (decrement register and skip if zero) instruction. The memory pointer registers X, SP and B are memory mapped into this space at address locations 0FC to 0FE Hex respectively, with the other registers (except 0FF) being available for general usage. 5.0 Functional Description The architecture of the devices are a modified Harvard architecture. With the Harvard architecture, the program memory ROM is separated from the data store memory (RAM). Both ROM and RAM have their own separate addressing space with separate address buses. The architecture, though based on the Harvard architecture, permits transfer of data from ROM to RAM. The instruction set permits any bit in memory to be set, reset or tested. All I/O and registers (except A and PC) are memory mapped; therefore, I/O bits and register bits can be directly and individually set, reset and tested. The accumulator (A) bits can also be directly and individually tested. 5.1 CPU REGISTERS The CPU can do an 8-bit addition, subtraction, logical or shift operation in one instruction (tC) cycle time. There are six CPU registers: A is the 8-bit Accumulator Register PC is the 15-bit Program Counter Register PU is the upper 7 bits of the program counter (PC) PL is the lower 8 bits of the program counter (PC) B is an 8-bit RAM address pointer, which can be optionally post auto incremented or decremented. X is an 8-bit alternate RAM address pointer, which can be optionally post auto incremented or decremented. S is the 8-bit Segment Address Register used to extend the lower half of the address range (00 to 7F) into 256 data segments of 128 bytes each. SP is the 8-bit stack pointer, which points to the subroutine/ interrupt stack (in RAM). With reset the SP is initialized to RAM address 02F Hex (devices with 64 bytes of RAM), or initialized to RAM address 06F Hex (devices with 128 bytes of RAM). All the CPU registers are memory mapped with the exception of the Accumulator (A) and the Program Counter (PC). Note: RAM contents are undefined upon power-up. 5.4 DATA MEMORY SEGMENT RAM EXTENSION Data memory address 0FF is used as a memory mapped location for the Data Segment Address Register (S). The data store memory is either addressed directly by a single byte address within the instruction, or indirectly relative to the reference of the B, X, or SP pointers (each contains a single-byte address). This single-byte address allows an addressing range of 256 locations from 00 to FF hex. The upper bit of this single-byte address divides the data store memory into two separate sections as outlined previously. With the exception of the RAM register memory from address locations 00F0 to 00FF, all RAM memory is memory mapped with the upper bit of the single-byte address being equal to zero. This allows the upper bit of the single-byte address to determine whether or not the base address range (from 0000 to 00FF) is extended. If this upper bit equals one (representing address range 0080 to 00FF), then address extension does not take place. Alternatively, if this upper bit equals zero, then the data segment extension register S is used to extend the base address range (from 0000 to 007F) from XX00 to XX7F, where XX represents the 8 bits from the S register. Thus the 128-byte data segment extensions are located from addresses 0100 to 017F for data segment 1, 0200 to 027F for data segment 2, etc., up to FF00 to FF7F for data segment 255. The base address range from 0000 to 007F represents data segment 0. 5.2 PROGRAM MEMORY The program memory consists of varies sizes of ROM. These bytes may hold program instructions or constant data (data tables for the LAID instruction, jump vectors for the JID instruction, and interrupt vectors for the VIS instruction). The program memory is addressed by the 15-bit program counter (PC). All interrupts in the device vector to program memory location 0FF Hex. The contents of the program memory read 00 Hex in the erased state. Program execution starts at location 0 after RESET. Figure 7 illustrates how the S register data memory extension is used in extending the lower half of the base address range (00 to 7F hex) into 256 data segments of 128 bytes each, with a total addressing range of 32 kbytes from XX00 to XX7F. This organization allows a total of 256 data segments of 128 bytes each with an additional upper base segment of 128 bytes. Furthermore, all addressing modes are available for all data segments. The S register must be changed under program control to move from one data segment (128 bytes) to another. However, the upper base segment (containing the 16 memory registers, I/O registers, control registers, etc.) is always available regardless of the contents of the S register, since the upper base segment (address range 0080 to 00FF) is independent of data segment extension. 5.3 DATA MEMORY The data memory address space includes the on-chip RAM and data registers, the I/O registers (Configuration, Data and Pin), the control registers, the MICROWIRE/PLUS SIO shift register, and the various registers, and counters associated with the timers (with the exception of the IDLE timer). Data memory is addressed directly by the instruction or indirectly by the B, X and SP pointers. The data memory consists of 256 or 512 bytes of RAM. Sixteen bytes of RAM are mapped as "registers" at ad- www.national.com 16 COP8SG Family 5.0 Functional Description (Continued) 10131745 FIGURE 7. RAM Organization The instructions that utilize the stack pointer (SP) always reference the stack as part of the base segment (Segment 0), regardless of the contents of the S register. The S register is not changed by these instructions. Consequently, the stack (used with subroutine linkage and interrupts) is always located in the base segment. The stack pointer will be initialized to point at data memory location 006F as a result of reset. The 128 bytes of RAM contained in the base segment are split between the lower and upper base segments. The first 112 bytes of RAM are resident from address 0000 to 006F in the lower base segment, while the remaining 16 bytes of RAM represent the 16 data memory registers located at addresses 00F0 to 00FF of the upper base segment. No RAM is located at the upper sixteen addresses (0070 to 007F) of the lower base segment. Additional RAM beyond these initial 128 bytes, however, will always be memory mapped in groups of 128 bytes (or less) at the data segment address extensions (XX00 to XX7F) of the lower base segment. The additional 384 bytes of RAM in this device are memory mapped at address locations 0100 to 017F, 0200 to 027F and 0300 to 037F hex. Memory address ranges 0200 to 027F and 0300 to 037F are unavailable on the COP8SGx5 and, if read, will return underfined data. The format of the ECON register is as follows: 5.5 ECON (CONFIGURATION) REGISTER For compatibility with COP8SGx7 devices, mask options are defined by an ECON Configuration Register which is programmed at the same time as the program code. Therefore, the register is programmed at the same time as the program memory. Bit 2 Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 X POR SECURITY CKI 2 CKI 1 WATCH F-Port HALT DOG Bit 7 =x Bit 6 =1 =0 Bit 5 =1 Bits 4, 3 = 0, 0 = 0, 1 = 1, 0 = 1, 1 =1 =0 Bit 1 17 =1 This is for factory test. The polarity is "Don't Care." Power-on reset enabled. Power-on reset disabled. Security enabled. External CKI option selected. G7 is available as a HALT restart and/or general purpose input. CKI is clock input. R/C oscillator option selected. G7 is available as a HALT restart and/or general purpose input. CKI clock input. Internal R/C components are supplied for maximum R/C frequency. Crystal oscillator with on-chip crystal bias resistor disabled. G7 (CKO) is the clock generator output to crystal/resonator. Crystal oscillator with on-chip crystal bias resistor enabled. G7 (CKO) is the clock generator output to crystal/resonator. WATCHDOG feature disabled. G1 is a general purpose I/O. WATCHDOG feature enabled. G1 pin is WATCHDOG output with weak pullup. Force port I compatibility. Disable port F outputs and pull-ups. This is intended for compatibility with existing code and Mask ROMMed devices only. This bit should be www.national.com COP8SG Family 5.0 Functional Description Bit 0 The recommended erasure procedure for windowed devices is exposure to short wave ultraviolet light which has a wavelength of 2537 Angstroms (A). The integrated dose (i.e. UV intensity X exposure time) for erasure should be a minimum of 15W-sec/cm2. (Continued) =0 programmed to 0 for all other applications. Enable full port F capability. =1 HALT mode disabled. =0 HALT mode enabled. 5.9 RESET The devices are initialized when the RESET pin is pulled low or the On-chip Power-On Reset is enabled. 5.6 USER STORAGE SPACE IN EPROM The ECON register is outside of the normal address range of the ROM and can not be accessed by the executing software. The COP8 assembler defines a special ROM section type, CONF, into which the ECON may be coded. Both ECON and User Data are programmed automatically by programmers that are certified by National. The following examples illustrate the declaration of ECON and the User information. Syntax: [label:] .sect econ, conf .db value ;1 byte, ;configures options .db <user information> .endsect ; up to 8 bytes Example: The following sets a value in the ECON register and User Identification for a COP8SGR728M7. The ECON bit values shown select options: Power-on enabled, Security disabled, Crystal oscillator with on-chip bias disabled, WATCHDOG enabled and HALT mode enabled. .sect econ, conf .db 0x55 ;por, xtal, wd, halt .db 'my v1.00' ;user data declaration .endsect 10131713 FIGURE 8. Reset Logic The following occurs upon initialization: Port L: TRI-STATE (High Impedance Input) Port C: TRI-STATE (High Impedance Input) Port G: TRI-STATE (High Impedance Input) Port F: TRI-STATE (High Impedance Input) Port D: HIGH PC: CLEARED to 0000 PSW, CNTRL and ICNTRL registers: CLEARED SIOR: UNAFFECTED after RESET with power already applied RANDOM after RESET at power-on T2CNTRL: CLEARED T3CNTRL: CLEARED Accumulator, Timer 1, Timer 2 and Timer 3: RANDOM after RESET with crystal clock option (power already applied) UNAFFECTED after RESET with R/C clock option (power already applied) RANDOM after RESET at power-on WKEN, WKEDG: CLEARED WKPND: RANDOM SP (Stack Pointer): Initialized to RAM address 06F Hex B and X Pointers: UNAFFECTED after RESET with power already applied RANDOM after RESET at power-on S Register: CLEARED RAM: UNAFFECTED after RESET with power already applied RANDOM after RESET at power-on USART: PSR, ENU, ENUR, ENUI: Cleared except the TBMT bit which is set to one. COMPARATORS: CMPSL; CLEARED WATCHDOG (if enabled): 5.7 OTP SECURITY The device has a security feature that, when enabled, prevents external reading of the OTP program memory. The security bit in the ECON register determines, whether security is enabled or disabled. If the security feature is disabled, the contents of the internal EPROM may be read. If the security feature is enabled, then any attempt to externally read the contents of the EPROM will result in the value FF Hex being read from all program locations Under no circumstances can a secured part be read. In addition, with the security feature enabled, the write operation to the EPROM program memory and ECON register is inhibited. The ECON register is readable regardless of the state of the security bit. The security bit, when set, cannot be erased, even in windowed packages. If the security bit is set in a device in a windowed package, that device may be erased but will not be further programmable. If security is being used, it is recommended that all other bits in the ECON register be programmed first. Then the security bit can be programmed. 5.8 ERASURE CHARACTERISTICS The erasure characteristics of the device are such that erasure begins to occur when exposed to light with wavelengths shorter than approximately 4000 Angstroms (A). It should be noted that sunlight and certain types of fluorescent lamps have wavelengths in the 3000A - 4000A range. After programming, opaque labels should be placed over the window of windowed devices to prevent unintentional erasure. Covering the window will also prevent temporary functional failure due to the generation of photo currents. www.national.com 18 RESET pin should be connected directly, or through a pull-up resistor, to VCC. The output of the power-on reset detector will always preset the Idle timer to 0FFF(4096 tC). At this time, the internal reset will be generated. (Continued) The device comes out of reset with both the WATCHDOG logic and the Clock Monitor detector armed, with the WATCHDOG service window bits set and the Clock Monitor bit set. The WATCHDOG and Clock Monitor circuits are inhibited during reset. The WATCHDOG service window bits being initialized high default to the maximum WATCHDOG service window of 64k tC clock cycles. The Clock Monitor bit being initialized high will cause a Clock Monitor error following reset if the clock has not reached the minimum specified frequency at the termination of reset. A Clock Monitor error will cause an active low error output on pin G1. This error output will continue until 16 tC-32 tC clock cycles following the clock frequency reaching the minimum specified value, at which time the G1 output will go high. If the Power-On Reset feature is enabled, the internal reset will not be turned off until the Idle timer underflows. The internal reset will perform the same functions as external reset. The user is responsible for ensuring that VCC is at the minimum level for the operating frequency within the 4096 tC. After the underflow, the logic is designed such that no additional internal resets occur as long as VCC remains above 2.0V. The contents of data registers and RAM are unknown following the on-chip reset. 5.9.1 External Reset The RESET input when pulled low initializes the device. The RESET pin must be held low for a minimum of one instruction cycle to guarantee a valid reset. During Power-Up initialization, the user must ensure that the RESET pin is held low until the device is within the specified VCC voltage. An R/C circuit on the RESET pin with a delay 5 times (5x) greater than the power supply rise time or 15 s whichever is greater, is recommended. Reset should also be wide enough to ensure crystal start-up upon Power-Up. RESET may also be used to cause an exit from the HALT mode. A recommended reset circuit for this device is shown in Figure 9. 10131714 RC > 5x power supply rise time or 15 s, whichever is greater. 10131715 FIGURE 9. Reset Circuit Using External Reset FIGURE 10. Reset Timing (Power-On Reset Enabled) with VCC Tied to RESET 5.9.2 On-Chip Power-On Reset The on-chip reset circuit is selected by a bit in the ECON register. When enabled, the device generates an internal reset as VCC rises to a voltage level above 2.0V. The on-chip reset circuitry is able to detect both fast and slow rise times on VCC (VCC rise time between 10 ns and 50 ms).To guarantee an on-chip power-on-reset, VCCmust start at a voltage less than the start voltage specified in the DC characteristics. Also, if VCC be lowered to the start voltage before powering back up to the operating range. If this is not possible, it is recommended that external reset be used. Under no circumstances should the RESET pin be allowed to float. If the on-chip Power-On Reset feature is being used, 10131716 FIGURE 11. Reset Circuit Using Power-On Reset 19 www.national.com COP8SG Family 5.0 Functional Description COP8SG Family 5.0 Functional Description specified duty cycle, rise and fall times, and input levels. G7/CKO is available as a general purpose input G7 and/or Halt control. Figure 13 shows the external oscillator connection diagram. (Continued) 5.10 OSCILLATOR CIRCUITS There are four clock oscillator options available: Crystal Oscillator with or without on-chip bias resistor, R/C Oscillator with on-chip resistor and capacitor, and External Oscillator. The oscillator feature is selected by programming the ECON register, which is summarized in Table 1. 5.10.3 R/C Oscillator The R/C Oscillator mode can be selected by programming ECON Bit 3 to 1 and ECON Bit 4 to 0. In R/C oscillation mode, CKI is left floating, while G7/CKO is available as a general purpose input G7 and/or HALT control. The R/C controlled oscillator has on-chip resistor and capacitor for maximum R/C oscillator frequency operation. The maximum frequency is 5 MHz 35% for VCC between 4.5V to 5.5V and temperature range of -40C to +85C. For max frequency operation, the CKI pin should be left floating. For lower frequencies, an external capacitor should be connected between CKI and either VCC or GND. Immunity of the R/C oscillator to external noise can be improved by connecting one half the external capacitance to VCC and one half to GND. PC board trace length on the CKI pin should be kept as short as possible. Table 3 shows the oscillator frequency as a function of external capacitance on the CKI pin. Figure 14 shows the R/C oscillator configuration. TABLE 1. Oscillator Option ECON4 ECON3 Oscillator Option 0 0 External Oscillator 1 0 Crystal Oscillator without Bias Resistor 0 1 R/C Oscillator 1 1 Crystal Oscillator with Bias Resistor 5.10.1 Crystal Oscillator The crystal Oscillator mode can be selected by programming ECON Bit 4 to 1. CKI is the clock input while G7/CKO is the clock generator output to the crystal. An on-chip bias resistor connected between CKI and CKO can be enabled by programming ECON Bit 3 to 1 with the crystal oscillator option selection. The value of the resistor is in the range of 0.5M to 2M (typically 1.0M). Table 2 shows the component values required for various standard crystal values. Resistor R2 is only used when the on-chip bias resistor is disabled. Figure 12 shows the crystal oscillator connection diagram. TABLE 3. R/C Oscillator Configuration, -40C to +85C, VCC = 4.5V to 5.5V, OSC Freq. Variation of 35% TABLE 2. Crystal Oscillator Configuration, TA = 25C, VCC = 5V R1 (k) R2 (M) C1 (pF) C2 (pF) CKI Freq. (MHz) 0 1 18 18 15 0 1 20 20 10 0 1 25 25 4 5.6 1 100 100-156 0.455 External Capacitor (pF)* R/C OSC Freq (MHz) Instr. Cycle (s) 0 5 2.0 9 4 2.5 52 2 5.0 125 1 10 6100 32 kHz 312.5 * Assumes 3-5 pF board capacitance. 5.10.2 External Oscillator The External Oscillator mode can be selected by programming ECON Bit 3 to 0 and ECON Bit 4 to 0. CKI can be driven by an external clock signal provided it meets the With On-Chip Bias Resistor Without On-Chip Bias Resistor 10131717 10131718 FIGURE 12. Crystal Oscillator www.national.com 20 PSW Register (Address X'00EF) (Continued) HC C T1PNDA T1ENA EXPND BUSY EXEN Bit 7 GIE Bit 0 The PSW register contains the following select bits: HC Half Carry Flag C Carry Flag T1PNDA Timer T1 Interrupt Pending Flag (Autoreload RA in mode 1, T1 Underflow in Mode 2, T1A capture edge in mode 3) T1ENA Timer T1 Interrupt Enable for Timer Underflow or T1A Input capture edge EXPND External interrupt pending BUSY MICROWIRE/PLUS busy shifting flag EXEN Enable external interrupt GIE Global interrupt enable (enables interrupts) 10131719 FIGURE 13. External Oscillator The Half-Carry flag is also affected by all the instructions that affect the Carry flag. The SC (Set Carry) and R/C (Reset Carry) instructions will respectively set or clear both the carry flags. In addition to the SC and R/C instructions, ADC, SUBC, RRC and RLC instructions affect the Carry and Half Carry flags. ICNTRL Register (Address X'00E8) 10131720 Reserved For operation at lower than maximum R/C oscillator frequency. LPEN T0PND T0EN WPND WEN T1PNDB Bit 7 T1ENB Bit 0 The ICNTRL register contains the following bits: Reserved This bit is reserved and must be zero LPEN L Port Interrupt Enable (Multi-Input Wakeup/Interrupt) T0PND Timer T0 Interrupt pending T0EN Timer T0 Interrupt Enable (Bit 12 toggle) WPND MICROWIRE/PLUS interrupt pending WEN Enable MICROWIRE/PLUS interrupt T1PNDB Timer T1 Interrupt Pending Flag for T1B capture edge T1ENB Timer T1 Interrupt Enable for T1B Input capture edge 10131721 For operation at maximum R/C oscillator frequency. FIGURE 14. R/C Oscillator 5.11 CONTROL REGISTERS T2CNTRL Register (Address X'00C6) CNTRL Register (Address X'00EE) T1C3 Bit 7 T1C2 T1C1 T1C0 MSEL T2C3 IEDG SL1 SL0 Bit 7 Bit 0 T2C2 T2C1 T2C0 T2PNDA T2ENA T2PNDB T2ENB Bit 0 The T2CNTRL control register contains the following bits: T2C3 Timer T2 mode control bit T2C2 Timer T2 mode control bit T2C1 Timer T2 mode control bit T2C0 Timer T2 Start/Stop control in timer modes 1 and 2, T2 Underflow Interrupt Pending Flag in timer mode 3 T2PNDA Timer T2 Interrupt Pending Flag (Autoreload RA in mode 1, T2 Underflow in mode 2, T2A capture edge in mode 3) T2ENA Timer T2 Interrupt Enable for Timer Underflow or T2A Input capture edge T2PNDB Timer T2 Interrupt Pending Flag for T2B capture edge T2ENB Timer T2 Interrupt Enable for Timer Underflow or T2B Input capture edge The Timer1 (T1) and MICROWIRE/PLUS control register contains the following bits: T1C3 Timer T1 mode control bit T1C2 Timer T1 mode control bit T1C1 Timer T1 mode control bit T1C0 Timer T1 Start/Stop control in timer modes 1 and 2, T1 Underflow Interrupt Pending Flag in timer mode 3 MSEL Selects G5 and G4 as MICROWIRE/PLUS signals SK and SO respectively IEDG External interrupt edge polarity select (0 = Rising edge, 1 = Falling edge) SL1 & SL0 Select the MICROWIRE/PLUS clock divide by (00 = 2, 01 = 4, 1x = 8) 21 www.national.com COP8SG Family 5.0 Functional Description COP8SG Family 5.0 Functional Description The control bits TxC3, TxC2, and TxC1 allow selection of the different modes of operation. (Continued) T3CNTRL Register (Address X'00B6) T3C3 T3C2 T3C1 Bit 7 T3C0 T3PNDA T3ENA T3PNDB 6.2.1 Mode 1. Processor Independent PWM Mode T3ENB One of the timer's operating modes is the Processor Independent PWM mode. In this mode, the timer generates a "Processor Independent" PWM signal because once the timer is setup, no more action is required from the CPU which translates to less software overhead and greater throughput. The user software services the timer block only when the PWM parameters require updating. This capability is provided by the fact that the timer has two separate 16-bit reload registers. One of the reload registers contains the "ON" timer while the other holds the "OFF" time. By contrast, a microcontroller that has only a single reload register requires an additional software to update the reload value (alternate between the on-time/off-time). The timer can generate the PWM output with the width and duty cycle controlled by the values stored in the reload registers. The reload registers control the countdown values and the reload values are automatically written into the timer when it counts down through 0, generating interrupt on each reload. Under software control and with minimal overhead, the PMW outputs are useful in controlling motors, triacs, the intensity of displays, and in providing inputs for data acquisition and sine wave generators. In this mode, the timer Tx counts down at a fixed rate of tC. Upon every underflow the timer is alternately reloaded with the contents of supporting registers, RxA and RxB. The very first underflow of the timer causes the timer to reload from the register RxA. Subsequent underflows cause the timer to be reloaded from the registers alternately beginning with the register RxB. Bit 0 The T3CNTRL control register contains the following bits: T3C3 Timer T3 mode control bit T3C2 Timer T3 mode control bit T3C1 Timer T3 mode control bit T3C0 Timer T3 Start/Stop control in timer modes 1 and 2, T3 Underflow Interrupt Pending Flag in timer mode 3 T3PNDA Timer T3 Interrupt Pending Flag (Autoreload RA in mode 1, T3 Underflow in mode 2, T3A capture edge in mode 3) T3ENA Timer T3 Interrupt Enable for Timer Underflow or T3A Input capture edge T3PNDB Timer T3 Interrupt Pending Flag for T3B capture edge T3ENB Timer T3 Interrupt Enable for Timer Underflow or T3B Input capture edge 6.0 Timers Each device contains a very versatile set of timers (T0, T1, T2 and T3). Timer T1, T2 and T3 and associated autoreload/ capture registers power up containing random data. 6.1 TIMER T0 (IDLE TIMER) Each device supports applications that require maintaining real time and low power with the IDLE mode. This IDLE mode support is furnished by the IDLE timer T0. The Timer T0 runs continuously at the fixed rate of the instruction cycle clock, tC. The user cannot read or write to the IDLE Timer T0, which is a count down timer. The Timer T0 supports the following functions: Figure 15 shows a block diagram of the timer in PWM mode. The underflows can be programmed to toggle the TxA output pin. The underflows can also be programmed to generate interrupts. Underflows from the timer are alternately latched into two pending flags, TxPNDA and TxPNDB. The user must reset these pending flags under software control. Two control enable flags, TxENA and TxENB, allow the interrupts from the timer underflow to be enabled or disabled. Setting the timer enable flag TxENA will cause an interrupt when a timer underflow causes the RxA register to be reloaded into the timer. Setting the timer enable flag TxENB will cause an interrupt when a timer underflow causes the RxB register to be reloaded into the timer. Resetting the timer enable flags will disable the associated interrupts. Either or both of the timer underflow interrupts may be enabled. This gives the user the flexibility of interrupting once per PWM period on either the rising or falling edge of the PWM output. Alternatively, the user may choose to interrupt on both edges of the PWM output. * Exit out of the Idle Mode (See Idle Mode description) * WATCHDOG logic (See WATCHDOG description) * Start up delay out of the HALT mode * Timing the width of the internal power-on-reset The IDLE Timer T0 can generate an interrupt when the twelfth bit toggles. This toggle is latched into the T0PND pending flag, and will occur every 2.731 ms at the maximum clock frequency (tC = 0.67 s). A control flag T0EN allows the interrupt from the twelfth bit of Timer T0 to be enabled or disabled. Setting T0EN will enable the interrupt, while resetting it will disable the interrupt. 6.2 TIMER T1, TIMER T2 and TIMER T3 Each device have a set of three powerful timer/counter blocks, T1, T2 and T3. Since T1, T2, and T3 are identical, all comments are equally applicable to any of the three timer blocks which will be referred to as Tx. Each timer block consists of a 16-bit timer, Tx, and two supporting 16-bit autoreload/capture registers, RxA and RxB. Each timer block has two pins associated with it, TxA and TxB. The pin TxA supports I/O required by the timer block, while the pin TxB is an input to the timer block. The timer block has three operating modes: Processor Independent PWM mode, External Event Counter mode, and Input Capture mode. www.national.com 6.2.2 Mode 2. External Event Counter Mode This mode is quite similar to the processor independent PWM mode described above. The main difference is that the timer, Tx, is clocked by the input signal from the TxA pin. The Tx timer control bits, TxC3, TxC2 and TxC1 allow the timer to be clocked either on a positive or negative edge from the TxA pin. Underflows from the timer are latched into the TxPNDA pending flag. Setting the TxENA control flag will cause an interrupt when the timer underflows. 22 value when the external event occurs, the time of the external event is recorded. Most microcontrollers have a latency time because they cannot determine the timer value when the external event occurs. The capture register eliminates the latency time, thereby allowing the applications program to retrieve the timer value stored in the capture register. (Continued) In this mode, the timer Tx is constantly running at the fixed tC rate. The two registers, RxA and RxB, act as capture registers. Each register acts in conjunction with a pin. The register RxA acts in conjunction with the TxA pin and the register RxB acts in conjunction with the TxB pin. The timer value gets copied over into the register when a trigger event occurs on its corresponding pin. Control bits, TxC3, TxC2 and TxC1, allow the trigger events to be specified either as a positive or a negative edge. The trigger condition for each input pin can be specified independently. The trigger conditions can also be programmed to generate interrupts. The occurrence of the specified trigger condition on the TxA and TxB pins will be respectively latched into the pending flags, TxPNDA and TxPNDB. The control flag TxENA allows the interrupt on TxA to be either enabled or disabled. Setting the TxENA flag enables interrupts to be generated when the selected trigger condition occurs on the TxA pin. Similarly, the flag TxENB controls the interrupts from the TxB pin. Underflows from the timer can also be programmed to generate interrupts. Underflows are latched into the timer TxC0 pending flag (the TxC0 control bit serves as the timer underflow interrupt pending flag in the Input Capture mode). Consequently, the TxC0 control bit should be reset when entering the Input Capture mode. The timer underflow interrupt is enabled with the TxENA control flag. When a TxA interrupt occurs in the Input Capture mode, the user must check both the TxPNDA and TxC0 pending flags in order to determine whether a TxA input capture or a timer underflow (or both) caused the interrupt. 10131746 FIGURE 15. Timer in PWM Mode In this mode the input pin TxB can be used as an independent positive edge sensitive interrupt input if the TxENB control flag is set. The occurrence of a positive edge on the TxB input pin is latched into the TxPNDB flag. Figure 16 shows a block diagram of the timer in External Event Counter mode. Note: The PWM output is not available in this mode since the TxA pin is being used as the counter input clock. Figure 17 shows a block diagram of the timer T1 in Input Capture mode. Timer T2 and T3 are identical to T1. 10131747 FIGURE 16. Timer in External Event Counter Mode 6.2.3 Mode 3. Input Capture Mode Each device can precisely measure external frequencies or time external events by placing the timer block, Tx, in the input capture mode. In this mode, the reload registers serve as independent capture registers, capturing the contents of the timer when an external event occurs (transition on the timer input pin). The capture registers can be read while maintaining count, a feature that lets the user measure elapsed time and time between events. By saving the timer 10131748 FIGURE 17. Timer in Input Capture Mode 23 www.national.com COP8SG Family 6.0 Timers COP8SG Family 6.0 Timers TxPNDA Timer Interrupt Pending Flag (Continued) TxENA 6.3 TIMER CONTROL FLAGS 1 = Timer Interrupt Enabled 0 = Timer Interrupt Disabled The control bits and their functions are summarized below. TxC3 Timer mode control TxC2 Timer mode control TxC1 TxC0 Timer mode control Timer Start/Stop control in Modes 1 and 2 (Processor Independent PWM and External Event Counter), where 1 = Start, 0 = Stop Timer Underflow Interrupt Pending Flag in Mode 3 (Input Capture) Mode 1 2 TxENB Timer Interrupt Enable Flag 1 = Timer Interrupt Enabled 0 = Timer Interrupt Disabled The timer mode control bits (TxC3, TxC2 and TxC1) are detailed below: Interrupt B Source Timer Counts On TxC1 1 0 1 PWM: TxA Toggle Autoreload RA Autoreload RB 1 0 0 PWM: No TxA Toggle Autoreload RA Autoreload RB 0 0 0 External Event Counter Timer Underflow Pos. TxB Edge Pos. TxA Edge 0 0 1 External Event Counter Timer Underflow Pos. TxB Edge Pos. TxA Edge 0 1 0 Captures: Pos. TxA Edge Pos. TxB Edge tC tC 0 1 1 1 0 1 1 Description Interrupt A Source TxC2 1 www.national.com TxPNDB Timer Interrupt Pending Flag TxC3 1 3 Timer Interrupt Enable Flag TxA Pos. Edge or Timer TxB Pos. Edge Underflow Captures: Pos. TxA Neg. TxB TxA Pos. Edge Edge or Timer Edge TxB Neg. Edge Underflow Captures: Neg. TxA Neg. TxB TxA Neg. Edge Edge or Timer Edge TxB Neg. Edge Underflow Captures: Neg. TxA Neg. TxB TxA Neg. Edge Edge or Timer Edge TxB Neg. Edge Underflow 24 tC tC tC tC Today, the proliferation of battery-operated based applications has placed new demands on designers to drive power consumption down. Battery-operated systems are not the only type of applications demanding low power. The power budget constraints are also imposed on those consumer/ industrial applications where well regulated and expensive power supply costs cannot be tolerated. Such applications rely on low cost and low power supply voltage derived directly from the "mains" by using voltage rectifier and passive components. Low power is demanded even in automotive applications, due to increased vehicle electronics content. This is required to ease the burden from the car battery. Low power 8-bit microcontrollers supply the smarts to control battery-operated, consumer/industrial, and automotive applications. Each device offers system designers a variety of low-power consumption features that enable them to meet the demanding requirements of today's increasing range of low-power applications. These features include low voltage operation, low current drain, and power saving features such as HALT, IDLE, and Multi-Input wakeup (MIWU). Each device offers the user two power save modes of operation: HALT and IDLE. In the HALT mode, all microcontroller activities are stopped. In the IDLE mode, the on-board oscillator circuitry and timer T0 are active but all other microcontroller activities are stopped. In either mode, all on-board RAM, registers, I/O states, and timers (with the exception of T0) are unaltered. Clock Monitor, if enabled, can be active in both modes. If a crystal or ceramic resonator may be selected as the oscillator, the Wakeup signal is not allowed to start the chip running immediately since crystal oscillators and ceramic resonators have a delayed start up time to reach full amplitude and frequency stability. The IDLE timer is used to generate a fixed delay to ensure that the oscillator has indeed stabilized before allowing instruction execution. In this case, upon detecting a valid Wakeup signal, only the oscillator circuitry is enabled. The IDLE timer is loaded with a value of 256 and is clocked with the tC instruction cycle clock. The tC clock is derived by dividing the oscillator clock down by a factor of 9. The Schmitt trigger following the CKI inverter on the chip ensures that the IDLE timer is clocked only when the oscillator has a sufficiently large amplitude to meet the Schmitt trigger specifications. This Schmitt trigger is not part of the oscillator closed loop. The start-up time-out from the IDLE timer enables the clock signals to be routed to the rest of the chip. If an R/C clock option is being used, the fixed delay is introduced optionally. A control bit, CLKDLY, mapped as configuration bit G7, controls whether the delay is to be introduced or not. The delay is included if CLKDLY is set, and excluded if CLKDLY is reset. The CLKDLY bit is cleared on reset. Each device has two options associated with the HALT mode. The first option enables the HALT mode feature, while the second option disables the HALT mode selected through bit 0 of the ECON register. With the HALT mode enable option, the device will enter and exit the HALT mode as described above. With the HALT disable option, the device cannot be placed in the HALT mode (writing a "1" to the HALT flag will have no effect, the HALT flag will remain "0"). The WATCHDOG detector circuit is inhibited during the HALT mode. However, the clock monitor circuit if enabled remains active during HALT mode in order to ensure a clock monitor error if the device inadvertently enters the HALT mode as a result of a runaway program or power glitch. If the device is placed in the HALT mode, with the R/C oscillator selected, the clock input pin (CKI) is forced to a logic high internally. With the crystal or external oscillator the CKI pin is TRI-STATE. It is recommended that the user not halt the device by merely stopping the clock in external oscillator mode. If this method is used, there is a possibility of greater than specified HALT current. If the user wishes to stop an external clock, it is recommended that the CPU be halted by setting the Halt flag first and the clock be stopped only after the CPU has halted. 7.1 HALT MODE Each device can be placed in the HALT mode by writing a "1" to the HALT flag (G7 data bit). All microcontroller activities, including the clock and timers, are stopped. The WATCHDOG logic on the devices are disabled during the HALT mode. However, the clock monitor circuitry, if enabled, remains active and will cause the WATCHDOG output pin (WDOUT) to go low. If the HALT mode is used and the user does not want to activate the WDOUT pin, the Clock Monitor should be disabled after the devices come out of reset (resetting the Clock Monitor control bit with the first write to the WDSVR register). In the HALT mode, the power requirements of the devices are minimal and the applied voltage (VCC) may be decreased to Vr (Vr = 2.0V) without altering the state of the machine. Each device supports three different ways of exiting the HALT mode. The first method of exiting the HALT mode is with the Multi-Input Wakeup feature on Port L. The second method is with a low to high transition on the CKO (G7) pin. This method precludes the use of the crystal clock configuration (since CKO becomes a dedicated output), and so may only be used with an R/C clock configuration. The third method of exiting the HALT mode is by pulling the RESET pin low. 25 www.national.com COP8SG Family On wakeup from G7 or Port L, the devices resume execution from the HALT point. On wakeup from RESET execution will resume from location PC=0 and all RESET conditions apply. 7.0 Power Saving Features COP8SG Family 7.0 Power Saving Features (Continued) 10131725 FIGURE 18. Wakeup from HALT 7.2 IDLE MODE The device is placed in the IDLE mode by writing a "1" to the IDLE flag (G6 data bit). In this mode, all activities, except the associated on-board oscillator circuitry and the IDLE Timer T0, are stopped. As with the HALT mode, the device can be returned to normal operation with a reset, or with a Multi-Input Wakeup from the L Port. Alternately, the microcontroller resumes normal operation from the IDLE mode when the twelfth bit (representing 4.096 ms at internal clock frequency of 10 MHz, tC = 1 s) of the IDLE Timer toggles. This toggle condition of the twelfth bit of the IDLE Timer T0 is latched into the T0PND pending flag. The user has the option of being interrupted with a transition on the twelfth bit of the IDLE Timer T0. The interrupt can be enabled or disabled via the T0EN control bit. Setting the T0EN flag enables the interrupt and vice versa. The user can enter the IDLE mode with the Timer T0 interrupt enabled. In this case, when the T0PND bit gets set, the device will first execute the Timer T0 interrupt service routine and then return to the instruction following the "Enter Idle Mode" instruction. Alternatively, the user can enter the IDLE mode with the IDLE Timer T0 interrupt disabled. In this case, the device will resume normal operation with the instruction immediately following the "Enter IDLE Mode" instruction. Note: It is necessary to program two NOP instructions following both the set HALT mode and set IDLE mode instructions. These NOP instructions are necessary to allow clock resynchronization following the HALT or IDLE modes. 10131726 FIGURE 19. Wakeup from IDLE www.national.com 26 to negative (high going low) for L Port bit 5, where bit 5 has previously been enabled for an input interrupt. The program would be as follows: (Continued) 7.3 MULTI-INPUT WAKEUP The Multi-Input Wakeup feature is used to return (wakeup) the device from either the HALT or IDLE modes. Alternately Multi-Input Wakeup/Interrupt feature may also be used to generate up to 8 edge selectable external interrupts. RBIT SBIT RBIT SBIT Figure 20 shows the Multi-Input Wakeup logic. The Multi-Input Wakeup feature utilizes the L Port. The user selects which particular L port bit (or combination of L Port bits) will cause the device to exit the HALT or IDLE modes. The selection is done through the register WKEN. The register WKEN is an 8-bit read/write register, which contains a control bit for every L port bit. Setting a particular WKEN bit enables a Wakeup from the associated L port pin. The user can select whether the trigger condition on the selected L Port pin is going to be either a positive edge (low to high transition) or a negative edge (high to low transition). This selection is made via the register WKEDG, which is an 8-bit control register with a bit assigned to each L Port pin. Setting the control bit will select the trigger condition to be a negative edge on that particular L Port pin. Resetting the bit selects the trigger condition to be a positive edge. Changing an edge select entails several steps in order to avoid a Wakeup condition as a result of the edge change. First, the associated WKEN bit should be reset, followed by the edge select change in WKEDG. Next, the associated WKPND bit should be cleared, followed by the associated WKEN bit being re-enabled. An example may serve to clarify this procedure. Suppose we wish to change the edge select from positive (low going high) 5, 5, 5, 5, WKEN WKEDG WKPND WKEN ; ; ; ; Disable MIWU Change edge polarity Reset pending flag Enable MIWU If the L port bits have been used as outputs and then changed to inputs with Multi-Input Wakeup/Interrupt, a safety procedure should also be followed to avoid wakeup conditions. After the selected L port bits have been changed from output to input but before the associated WKEN bits are enabled, the associated edge select bits in WKEDG should be set or reset for the desired edge selects, followed by the associated WKPND bits being cleared. This same procedure should be used following reset, since the L port inputs are left floating as a result of reset. The occurrence of the selected trigger condition for MultiInput Wakeup is latched into a pending register called WKPND. The respective bits of the WKPND register will be set on the occurrence of the selected trigger edge on the corresponding Port L pin. The user has the responsibility of clearing these pending flags. Since WKPND is a pending register for the occurrence of selected wakeup conditions, the device will not enter the HALT mode if any Wakeup bit is both enabled and pending. Consequently, the user must clear the pending flags before attempting to enter the HALT mode. WKEN and WKEDG are all read/write registers, and are cleared at reset. WKPND register contains random value after reset. 10131727 FIGURE 20. Multi-Input Wake Up Logic 27 www.national.com COP8SG Family 7.0 Power Saving Features COP8SG Family Other functions of the ENUR register include saving the ninth bit received in the data frame, enabling or disabling the USART's attention mode of operation and providing additional receiver/transmitter status information via RCVG and XMTG bits. The determination of an internal or external clock source is done by the ENUI register, as well as selecting the number of stop bits and enabling or disabling transmit and receive interrupts. A control flag in this register can also select the USART mode of operation: asynchronous or synchronous. 8.0 USART Each device contains a full-duplex software programmable USART. The USART (Figure 21) consists of a transmit shift register, a receive shift register and seven addressable registers, as follows: a transmit buffer register (TBUF), a receiver buffer register (RBUF), a USART control and status register (ENU), a USART receive control and status register (ENUR), a USART interrupt and clock source register (ENUI), a prescaler select register (PSR) and baud (BAUD) register. The ENU register contains flags for transmit and receive functions; this register also determines the length of the data frame (7, 8 or 9 bits), the value of the ninth bit in transmission, and parity selection bits. The ENUR register flags framing, data overrun and parity errors while the USART is receiving. 10131739 FIGURE 21. USART Block Diagram 8.1 USART CONTROL AND STATUS REGISTERS The operation of the USART is programmed through three registers: ENU, ENUR and ENUI. 8.2 DESCRIPTION OF USART REGISTER BITS ENU-USART Control and Status Register (Address at 0BA) PEN PSEL1 XBIT9/ CHL1 CHL0 ERR RBFL TBMT PSEL0 Bit 7 www.national.com 28 Bit 0 the last time the ENUR register was read. (Continued) PE = 1 PEN: This bit enables/disables Parity (7- and 8-bit modes only). Read/Write, cleared on reset. PEN = 0 Parity disabled. PEN = 1 SPARE: Reserved for future use. Read/Write, cleared on reset. RBIT9: Contains the ninth data bit received when the USART is operating with nine data bits per frame. Read only, cleared on reset. ATTN: ATTENTION Mode is enabled while this bit is set. This bit is cleared automatically on receiving a character with data bit nine set. Read/Write, cleared on reset. XMTG: This bit is set to indicate that the USART is transmitting. It gets reset at the end of the last frame (end of last Stop bit). Read only, cleared on reset. RCVG: This bit is set high whenever a framing error occurs and goes low when RDX goes high. Read only, cleared on reset. ENUI-USART Interrupt and Clock Source Register (Address at 0BC) Parity enabled. PSEL1, PSEL0: Parity select bits. Read/Write, cleared on reset. PSEL1 = 0, PSEL0 = 0 Odd Parity (if Parity enabled) PSEL1 = 0, PSEL0 = 1 Even Parity (if Parity enabled) PSEL1 = 1, PSEL0 = 0 Mark(1) (if Parity enabled) PSEL1 = 1, PSEL0 = 1 Space(0) (if Parity enabled) XBIT9/PSEL0: Programs the ninth bit for transmission when the USART is operating with nine data bits per frame. For seven or eight data bits per frame, this bit in conjunction with PSEL1 selects parity. Read/Write, cleared on reset. CHL1, CHL0: These bits select the character frame format. Parity is not included and is generated/verified by hardware. Read/Write, cleared on reset. CHL1 = 0, CHL0 = 0 The frame contains eight data bits. CHL1 = 0, CHL0 = 1 The frame contains seven data bits. CHL1 = 1, CHL0 = 0 The frame contains nine data bits. CHL1 = 1, CHL0 = 1 Loopback Mode selected. Transmitter output internally looped back to receiver input. Nine bit framing format is used. STP2 Bit 7 FE PE Reserved RBIT9 ATTN SSEL XRCLK XTCLK ERI ETI Bit 0 STP78: This bit is set to program the last Stop bit to be 7/8th of a bit in length. Read/Write, cleared on reset. ETDX: TDX (USART Transmit Pin) is the alternate function assigned to Port L pin L2; it is selected by setting ETDX bit. To simulate line break generation, software should reset ETDX bit and output logic zero to TDX pin through Port L data and configuration registers. Read/Write, cleared on reset. SSEL: USART mode select. Read/Write, cleared on reset. SSEL = 0 Asynchronous Mode. SSEL = 1 Synchronous Mode. XRCLK: This bit selects the clock source for the receiver section. Read/Write, cleared on reset. XRCLK = 0 The clock source is selected through the PSR and BAUD registers. XRCLK = 1 Signal on CKX (L1) pin is used as the clock. XMTG RCVG XTCLK: This bit selects the clock source for the transmitter section. Read/Write, cleared on reset. XTCLK = 0 The clock source is selected through the PSR and BAUD registers. XTCLK = 1 Signal on CKX (L1) pin is used as the clock. (Note 16) Bit 7 STP78 ETDX STP2: This bit programs the number of Stop bits to be transmitted. Read/Write, cleared on reset. STP2 = 0 One Stop bit transmitted. STP2 = 1 Two Stop bits transmitted. ERR: This bit is a global USART error flag which gets set if any or a combination of the errors (DOE, FE, PE) occur. Read only; it cannot be written by software, cleared on reset. RBFL: This bit is set when the USART has received a complete character and has copied it into the RBUF register. It is automatically reset when software reads the character from RBUF. Read only; it cannot be written by software, cleared on reset. TBMT: This bit is set when the USART transfers a byte of data from the TBUF register into the TSFT register for transmission. It is automatically reset when software writes into the TBUF register. Read only, bit is set to "one" on reset; it cannot be written by software. ENUR-USART Receive Control and Status Register (Address at 0BB) DOE Indicates the occurrence of a Parity Error. Bit 0 Note 16: Bit is reserved for future use. User must set to zero. DOE: Flags a Data Overrun Error. Read only, cleared on read, cleared on reset. DOE = 0 Indicates no Data Overrun Error has been detected since the last time the ENUR register was read. DOE = 1 Indicates the occurrence of a Data Overrun Error. ERI: This bit enables/disables interrupt from the receiver section. Read/Write, cleared on reset. ERI = 0 Interrupt from the receiver is disabled. ERI = 1 Interrupt from the receiver is enabled. ETI: This bit enables/disables interrupt from the transmitter section. Read/Write, cleared on reset. ETI = 0 Interrupt from the transmitter is disabled. ETI = 1 Interrupt from the transmitter is enabled. FE: Flags a Framing Error. Read only, cleared on read, cleared on reset. FE = 0 Indicates no Framing Error has been detected since the last time the ENUR register was read. FE = 1 Indicates the occurrence of a Framing Error. PE: Flags a Parity Error. Read only, cleared on read, cleared on reset. PE = 0 Indicates no Parity Error has been detected since 29 www.national.com COP8SG Family 8.0 USART COP8SG Family 8.0 USART This mode is selected by setting SSEL bit in the ENUI register. The input frequency to the USART is the same as the baud rate. When an external clock input is selected at the CKX pin, data transmit and receive are performed synchronously with this clock through TDX/RDX pins. If data transmit and receive are selected with the CKX pin as clock output, the device generates the synchronous clock output at the CKX pin. The internal baud rate generator is used to produce the synchronous clock. Data transmit and receive are performed synchronously with this clock. (Continued) 8.3 Associated I/O Pins Data is transmitted on the TDX pin and received on the RDX pin. TDX is the alternate function assigned to Port L pin L2; it is selected by setting ETDX (in the ENUI register) to one. RDX is an inherent function of Port L pin L3, requiring no setup. The baud rate clock for the USART can be generated onchip, or can be taken from an external source. Port L pin L1 (CKX) is the external clock I/O pin. The CKX pin can be either an input or an output, as determined by Port L Configuration and Data registers (Bit 1). As an input, it accepts a clock signal which may be selected to drive the transmitter and/or receiver. As an output, it presents the internal Baud Rate Generator output. 8.5 FRAMING FORMATS The USART supports several serial framing formats (Figure 22). The format is selected using control bits in the ENU, ENUR and ENUI registers. The first format (1, 1a, 1b, 1c) for data transmission (CHL0 = 1, CHL1 = 0) consists of Start bit, seven Data bits (excluding parity) and 7/8, one or two Stop bits. In applications using parity, the parity bit is generated and verified by hardware. The second format (CHL0 = 0, CHL1 = 0) consists of one Start bit, eight Data bits (excluding parity) and 7/8, one or two Stop bits. Parity bit is generated and verified by hardware. The third format for transmission (CHL0 = 0, CHL1 = 1) consists of one Start bit, nine Data bits and 7/8, one or two Stop bits. This format also supports the USART "ATTENTION" feature. When operating in this format, all eight bits of TBUF and RBUF are used for data. The ninth data bit is transmitted and received using two bits in the ENU and ENUR registers, called XBIT9 and RBIT9. RBIT9 is a read only bit. Parity is not generated or verified in this mode. For any of the above framing formats, the last Stop bit can be programmed to be 7/8th of a bit in length. If two Stop bits are selected and the 7/8th bit is set (selected), the second Stop bit will be 7/8th of a bit in length. The parity is enabled/disabled by PEN bit located in the ENU register. Parity is selected for 7- and 8-bit modes only. If parity is enabled (PEN = 1), the parity selection is then performed by PSEL0 and PSEL1 bits located in the ENU register. Note that the XBIT9/PSEL0 bit located in the ENU register serves two mutually exclusive functions. This bit programs the ninth bit for transmission when the USART is operating with nine data bits per frame. There is no parity selection in this framing format. For other framing formats XBIT9 is not needed and the bit is PSEL0 used in conjunction with PSEL1 to select parity. The frame formats for the receiver differ from the transmitter in the number of Stop bits required. The receiver only requires one Stop bit in a frame, regardless of the setting of the Stop bit selection bits in the control register. Note that an implicit assumption is made for full duplex USART operation that the framing formats are the same for the transmitter and receiver. 8.4 USART Operation The USART has two modes of operation: asynchronous mode and synchronous mode. 8.4.1 ASYNCHRONOUS MODE This mode is selected by resetting the SSEL (in the ENUI register) bit to zero. The input frequency to the USART is 16 times the baud rate. The TSFT and TBUF registers double-buffer data for transmission. While TSFT is shifting out the current character on the TDX pin, the TBUF register may be loaded by software with the next byte to be transmitted. When TSFT finishes transmitting the current character the contents of TBUF are transferred to the TSFT register and the Transmit Buffer Empty Flag (TBMT in the ENU register) is set. The TBMT flag is automatically reset by the USART when software loads a new character into the TBUF register. There is also the XMTG bit which is set to indicate that the USART is transmitting. This bit gets reset at the end of the last frame (end of last Stop bit). TBUF is a read/write register. The RSFT and RBUF registers double-buffer data being received. The USART receiver continually monitors the signal on the RDX pin for a low level to detect the beginning of a Start bit. Upon sensing this low level, it waits for half a bit time and samples again. If the RDX pin is still low, the receiver considers this to be a valid Start bit, and the remaining bits in the character frame are each sampled a single time, at the mid-bit position. Serial data input on the RDX pin is shifted into the RSFT register. Upon receiving the complete character, the contents of the RSFT register are copied into the RBUF register and the Received Buffer Full Flag (RBFL) is set. RBFL is automatically reset when software reads the character from the RBUF register. RBUF is a read only register. There is also the RCVG bit which is set high when a framing error occurs and goes low once RDX goes high. TBMT, XMTG, RBFL and RCVG are read only bits. 8.4.2 SYNCHRONOUS MODE In this mode data is transferred synchronously with the clock. Data is transmitted on the rising edge and received on the falling edge of the synchronous clock. www.national.com 30 COP8SG Family 8.0 USART (Continued) 10131740 FIGURE 22. Framing Formats source selected in the PSR and BAUD registers. Internally, the basic baud clock is created from the oscillator frequency through a two-stage divider chain consisting of a 1-16 (increments of 0.5) prescaler and an 11-bit binary counter. (Figure 23). The divide factors are specified through two read/write registers shown in Figure 24. Note that the 11-bit Baud Rate Divisor spills over into the Prescaler Select Register (PSR). PSR is cleared upon reset. As shown in Table 5, a Prescaler Factor of 0 corresponds to NO CLOCK. This condition is the USART power down mode where the USART clock is turned off for power saving purpose. The user must also turn the USART clock off when a different baud rate is chosen. The correspondences between the 5-bit Prescaler Select and Prescaler factors are shown in Table 5. There are many ways to calculate the two divisor factors, but one particularly effective method would be to achieve a 1.8432 MHz frequency coming out of the first stage. The 1.8432 MHz prescaler output is then used to drive the software programmable baud rate counter to create a 16x clock for the following baud rates: 110, 134.5, 150, 300, 600, 1200, 1800, 2400, 3600, 4800, 7200, 9600, 19200 and 38400 (Table 4). Other baud 8.6 USART INTERRUPTS The USART is capable of generating interrupts. Interrupts are generated on Receive Buffer Full and Transmit Buffer Empty. Both interrupts have individual interrupt vectors. Two bytes of program memory space are reserved for each interrupt vector. The two vectors are located at addresses 0xEC to 0xEF Hex in the program memory space. The interrupts can be individually enabled or disabled using Enable Transmit Interrupt (ETI) and Enable Receive Interrupt (ERI) bits in the ENUI register. The interrupt from the Transmitter is set pending, and remains pending, as long as both the TBMT and ETI bits are set. To remove this interrupt, software must either clear the ETI bit or write to the TBUF register (thus clearing the TBMT bit). The interrupt from the receiver is set pending, and remains pending, as long as both the RBFL and ERI bits are set. To remove this interrupt, software must either clear the ERI bit or read from the RBUF register (thus clearing the RBFL bit). 8.7 Baud Clock Generation The clock inputs to the transmitter and receiver sections of the USART can be individually selected to come either from an external source at the CKX pin (port L, pin L1) or from a 31 www.national.com COP8SG Family 8.0 USART (Continued) rates may be created by using appropriate divisors. The 16x clock is then divided by 16 to provide the rate for the serial shift registers of the transmitter and receiver. 10131741 FIGURE 23. USART BAUD Clock Generation 10131742 FIGURE 24. USART BAUD Clock Divisor Registers TABLE 4. Baud Rate Divisors (1.8432 MHz Prescaler Output) Prescaler Select Factor 2.5 Baud Baud Rate 00100 Rate Divisor - 1 (N-1) 00101 3 00110 3.5 110 (110.03) 1046 134.5 (134.58) 855 150 767 300 383 600 191 1200 95 1800 63 2400 47 3600 31 4800 23 7200 15 9600 11 19200 5 38400 2 Note: The entries in Table 4 assume a prescaler output of 1.8432 MHz. In the asynchronous mode the baud rate could be as high as 987.5k. TABLE 5. Prescaler Factors www.national.com Prescaler Prescaler Prescaler Select Factor 00000 NO CLOCK 00001 1 00010 1.5 00011 2 32 00111 4 01000 4.5 01001 5 01010 5.5 01011 6 01100 6.5 01101 7 01110 7.5 01111 8 10000 8.5 10001 9 10010 9.5 10011 10 10100 10.5 10101 11 10110 11.5 10111 12 11000 12.5 11001 13 11010 13.5 11011 14 11100 14.5 11101 15 11110 15.5 11111 16 because of the finite start up time requirement of the crystal oscillator. The idle timer (T0) generates a fixed (256 tc) delay to ensure that the oscillator has indeed stabilized before allowing the device to execute code. The user has to consider this delay when data transfer is expected immediately after exiting the HALT mode. (Continued) As an example, considering Asynchronous Mode and a CKI clock of 4.608 MHz, the prescaler factor selected is: 4.608/1.8432 = 2.5 The 2.5 entry is available in Table 5. The 1.8432 MHz prescaler output is then used with proper Baud Rate Divisor (Table 4) to obtain different baud rates. For a baud rate of 19200 e.g., the entry in Table 4 is 5. N - 1 = 5 (N - 1 is the value from Table 4) 8.9 Diagnostic Bits CHARL0 and CHARL1 in the ENU register provide a loopback feature for diagnostic testing of the USART. When these bits are set to one, the following occur: The receiver input pin (RDX) is internally connected to the transmitter output pin (TDX); the output of the Transmitter Shift Register is "looped back" into the Receive Shift Register input. In this mode, data that is transmitted is immediately received. This feature allows the processor to verify the transmit and receive data paths of the USART. Note that the framing format for this mode is the nine bit format; one Start bit, nine data bits, and 7/8, one or two Stop bits. Parity is not generated or verified in this mode. N = 6 (N is the Baud Rate Divisor) Baud Rate = 1.8432 MHz/(16 x 6) = 19200 The divide by 16 is performed because in the asynchronous mode, the input frequency to the USART is 16 times the baud rate. The equation to calculate baud rates is given below. The actual Baud Rate may be found from: BR = Fc/(16 x N x P) Where: BR is the Baud Rate Fc is the CKI frequency N is the Baud Rate Divisor (Table 4). 8.10 Attention Mode The USART Receiver section supports an alternate mode of operation, referred to as ATTENTION Mode. This mode of operation is selected by the ATTN bit in the ENUR register. The data format for transmission must also be selected as having nine Data bits and either 7/8, one or two Stop bits. The ATTENTION mode of operation is intended for use in networking the device with other processors. Typically in such environments the messages consists of device addresses, indicating which of several destinations should receive them, and the actual data. This Mode supports a scheme in which addresses are flagged by having the ninth bit of the data field set to a 1. If the ninth bit is reset to a zero the byte is a Data byte. While in ATTENTION mode, the USART monitors the communication flow, but ignores all characters until an address character is received. Upon receiving an address character, the USART signals that the character is ready by setting the RBFL flag, which in turn interrupts the processor if USART Receiver interrupts are enabled. The ATTN bit is also cleared automatically at this point, so that data characters as well as address characters are recognized. Software examines the contents of the RBUF and responds by deciding either to accept the subsequent data stream (by leaving the ATTN bit reset) or to wait until the next address character is seen (by setting the ATTN bit again). Operation of the USART Transmitter is not affected by selection of this Mode. The value of the ninth bit to be transmitted is programmed by setting XBIT9 appropriately. The value of the ninth bit received is obtained by reading RBIT9. Since this bit is located in ENUR register where the error flags reside, a bit operation on it will reset the error flags. P is the Prescaler Divide Factor selected by the value in the Prescaler Select Register (Table 5) Note: In the Synchronous Mode, the divisor 16 is replaced by two. Example: Asynchronous Mode: Crystal Frequency = 5 MHz Desired baud rate = 9600 Using the above equation N x P can be calculated first. N x P = (5 x 106)/(16 x 9600) = 32.552 Now 32.552 is divided by each Prescaler Factor (Table 5) to obtain a value closest to an integer. This factor happens to be 6.5 (P = 6.5). N = 32.552/6.5 = 5.008 (N = 5) The programmed value (from Table 4) should be 4 (N - 1). Using the above values calculated for N and P: BR = (5 x 106)/(16 x 5 x 6.5) = 9615.384 % error = (9615.385 - 9600)/9600 x 100 = 0.16% 8.8 Effect of HALT/IDLE The USART logic is reinitialized when either the HALT or IDLE modes are entered. This reinitialization sets the TBMT flag and resets all read only bits in the USART control and status registers. Read/Write bits remain unchanged. The Transmit Buffer (TBUF) is not affected, but the Transmit Shift register (TSFT) bits are set to one. The receiver registers RBUF and RSFT are not affected. The device will exit from the HALT/IDLE modes when the Start bit of a character is detected at the RDX (L3) pin. This feature is obtained by using the Multi-Input Wakeup scheme provided on the device. Before entering the HALT or IDLE modes the user program must select the Wakeup source to be on the RDX pin. This selection is done by setting bit 3 of WKEN (Wakeup Enable) register. The Wakeup trigger condition is then selected to be high to low transition. This is done via the WKEDG register (Bit 3 is one.) If the device is halted and crystal oscillator is used, the Wakeup signal will not start the chip running immediately 9.0 Comparators The device contains two differential comparators, each with a pair of inputs (positive and negative) and an output. Ports F1-F3 and F4-F6 are used for the comparators. The following is the Port F assignment: F6 Comparator2 output F5 Comparator2 positive input F4 Comparator2 negative input F3 Comparator1 output F2 Comparator1 positive input 33 www.national.com COP8SG Family 8.0 USART COP8SG Family 9.0 Comparators F1 will read as zero if the associated comparator is not enabled. The Comparator Select Register is cleared with reset, resulting in the comparators being disabled. The comparators should also be disabled before entering either the HALT or IDLE modes in order to save power. The configuration of the CMPSL register is as follows: (Continued) Comparator1 negative input A Comparator Select Register (CMPSL) is used to enable the comparators, read the outputs of the comparators internally, and enable the outputs of the comparators to the pins. Two control bits (enable and output enable) and one result bit are associated with each comparator. The comparator result bits (CMP1RD and CMP2RD) are read only bits which Reserved CMP20E CMP2RD CMPSL REGISTER (ADDRESS X'00B7) CMP2EN CMP10E CMP1RD CMP1EN Reserved Bit 7 Bit 0 Note: For compatibility with existing code and with existing Mask ROMMed devices the bits of the CMPSL register will take precedence over the associated Port F configuration and data output bits. The CMPSL register contains the following bits: Reserved These bits are reserved and must be zero CMP20E Selects pin I6 as comparator 2 output provided that CMP2EN is set to enable the comparator CMP2RD Comparator 2 result (this is a read only bit, which will read as 0 if the comparator is not enabled) CMP2EN Enable comparator 2 CMP10E Selects pin I3 as comparator 1 output provided that CMPIEN is set to enable the comparator CMP1RD Comparator 1 result (this is a read only bit, which will read as 0 if the comparator is not enabled) CMP1EN Enable comparator 1 10.0 Interrupts 10.1 INTRODUCTION Each device supports thirteen vectored interrupts. Interrupt sources include Timer 0, Timer 1, Timer 2, Timer 3, Port L Wakeup, Software Trap, MICROWIRE/PLUS, and External Input. All interrupts force a branch to location 00FF Hex in program memory. The VIS instruction may be used to vector to the appropriate service routine from location 00FF Hex. The Software trap has the highest priority while the default VIS has the lowest priority. Each of the 13 maskable inputs has a fixed arbitration ranking and vector. Note that the two unused bits of CMPSL may be used as software flags. Note: If the user attempts to use the comparator output immediately after enabling the comparator, an incorrect value may be read. At least one instruction cycle should pass between these operations. The use of a direct addressing mode instruction for either of these two operations will guarantee this delay in the software. Figure 25 shows the Interrupt Block Diagram. 10131728 FIGURE 25. Interrupt Block Diagram www.national.com 34 interrupt, and jump to the interrupt handling routine corresponding to the highest priority enabled and active interrupt. Alternately, the user may choose to poll all interrupt pending and enable bits to determine the source(s) of the interrupt. If more than one interrupt is active, the user's program must decide which interrupt to service. (Continued) 10.2 MASKABLE INTERRUPTS All interrupts other than the Software Trap are maskable. Each maskable interrupt has an associated enable bit and pending flag bit. The pending bit is set to 1 when the interrupt condition occurs. The state of the interrupt enable bit, combined with the GIE bit determines whether an active pending flag actually triggers an interrupt. All of the maskable interrupt pending and enable bits are contained in mapped control registers, and thus can be controlled by the software. A maskable interrupt condition triggers an interrupt under the following conditions: 1. The enable bit associated with that interrupt is set. 2. The GIE bit is set. 3. The device is not processing a non-maskable interrupt. (If a non-maskable interrupt is being serviced, a maskable interrupt must wait until that service routine is completed.) An interrupt is triggered only when all of these conditions are met at the beginning of an instruction. If different maskable interrupts meet these conditions simultaneously, the highest priority interrupt will be serviced first, and the other pending interrupts must wait. Upon Reset, all pending bits, individual enable bits, and the GIE bit are reset to zero. Thus, a maskable interrupt condition cannot trigger an interrupt until the program enables it by setting both the GIE bit and the individual enable bit. When enabling an interrupt, the user should consider whether or not a previously activated (set) pending bit should be acknowledged. If, at the time an interrupt is enabled, any previous occurrences of the interrupt should be ignored, the associated pending bit must be reset to zero prior to enabling the interrupt. Otherwise, the interrupt may be simply enabled; if the pending bit is already set, it will immediately trigger an interrupt. A maskable interrupt is active if its associated enable and pending bits are set. An interrupt is an asychronous event which may occur before, during, or after an instruction cycle. Any interrupt which occurs during the execution of an instruction is not acknowledged until the start of the next normally executed instruction is to be skipped, the skip is performed before the pending interrupt is acknowledged. At the start of interrupt acknowledgment, the following actions occur: 1. The GIE bit is automatically reset to zero, preventing any subsequent maskable interrupt from interrupting the current service routine. This feature prevents one maskable interrupt from interrupting another one being serviced. 2. The address of the instruction about to be executed is pushed onto the stack. 3. The program counter (PC) is loaded with 00FF Hex, causing a jump to that program memory location. The device requires seven instruction cycles to perform the actions listed above. If the user wishes to allow nested interrupts, the interrupts service routine may set the GIE bit to 1 by writing to the PSW register, and thus allow other maskable interrupts to interrupt the current service routine. If nested interrupts are allowed, caution must be exercised. The user must write the program in such a way as to prevent stack overflow, loss of saved context information, and other unwanted conditions. The interrupt service routine stored at location 00FF Hex should use the VIS instruction to determine the cause of the Within a specific interrupt service routine, the associated pending bit should be cleared. This is typically done as early as possible in the service routine in order to avoid missing the next occurrence of the same type of interrupt event. Thus, if the same event occurs a second time, even while the first occurrence is still being serviced, the second occurrence will be serviced immediately upon return from the current interrupt routine. An interrupt service routine typically ends with an RETI instruction. This instruction sets the GIE bit back to 1, pops the address stored on the stack, and restores that address to the program counter. Program execution then proceeds with the next instruction that would have been executed had there been no interrupt. If there are any valid interrupts pending, the highest-priority interrupt is serviced immediately upon return from the previous interrupt. 10.3 VIS INSTRUCTION The general interrupt service routine, which starts at address 00FF Hex, must be capable of handling all types of interrupts. The VIS instruction, together with an interrupt vector table, directs the device to the specific interrupt handling routine based on the cause of the interrupt. VIS is a single-byte instruction, typically used at the very beginning of the general interrupt service routine at address 00FF Hex, or shortly after that point, just after the code used for context switching. The VIS instruction determines which enabled and pending interrupt has the highest priority, and causes an indirect jump to the address corresponding to that interrupt source. The jump addresses (vectors) for all possible interrupts sources are stored in a vector table. The vector table may be as long as 32 bytes (maximum of 16 vectors) and resides at the top of the 256-byte block containing the VIS instruction. However, if the VIS instruction is at the very top of a 256-byte block (such as at 00FF Hex), the vector table resides at the top of the next 256-byte block. Thus, if the VIS instruction is located somewhere between 00FF and 01DF Hex (the usual case), the vector table is located between addresses 01E0 and 01FF Hex. If the VIS instruction is located between 01FF and 02DF Hex, then the vector table is located between addresses 02E0 and 02FF Hex, and so on. Each vector is 15 bits long and points to the beginning of a specific interrupt service routine somewhere in the 32 kbyte memory space. Each vector occupies two bytes of the vector table, with the higher-order byte at the lower address. The vectors are arranged in order of interrupt priority. The vector of the maskable interrupt with the lowest rank is located to 0yE0 (higher-order byte) and 0yE1 (lower-order byte). The next priority interrupt is located at 0yE2 and 0yE3, and so forth in increasing rank. The Software Trap has the highest rank and its vector is always located at 0yFE and 0yFF. The number of interrupts which can become active defines the size of the table. Table 6 shows the types of interrupts, the interrupt arbitration ranking, and the locations of the corresponding vectors in the vector table. The vector table should be filled by the user with the memory locations of the specific interrupt service routines. For ex35 www.national.com COP8SG Family 10.0 Interrupts COP8SG Family 10.0 Interrupts gram context (A, B, X, etc.) and executing the RETI instruction, an interrupt service routine can be terminated by returning to the VIS instruction. In this case, interrupts will be serviced in turn until no further interrupts are pending and the default VIS routine is started. After testing the GIE bit to ensure that execution is not erroneous, the routine should restore the program context and execute the RETI to return to the interrupted program. This technique can save up to fifty instruction cycles (tc), or more, (50s at 10 MHz oscillator) of latency for pending interrupts with a penalty of fewer than ten instruction cycles if no further interrupts are pending. To ensure reliable operation, the user should always use the VIS instruction to determine the source of an interrupt. Although it is possible to poll the pending bits to detect the source of an interrupt, this practice is not recommended. The use of polling allows the standard arbitration ranking to be altered, but the reliability of the interrupt system is compromised. The polling routine must individually test the enable and pending bits of each maskable interrupt. If a Software Trap interrupt should occur, it will be serviced last, even though it should have the highest priority. Under certain conditions, a Software Trap could be triggered but not serviced, resulting in an inadvertent "locking out" of all maskable interrupts by the Software Trap pending flag. Problems such as this can be avoided by using VIS instruction. (Continued) ample, if the Software Trap routine is located at 0310 Hex, then the vector location 0yFE and -0yFF should contain the data 03 and 10 Hex, respectively. When a Software Trap interrupt occurs and the VIS instruction is executed, the program jumps to the address specified in the vector table. The interrupt sources in the vector table are listed in order of rank, from highest to lowest priority. If two or more enabled and pending interrupts are detected at the same time, the one with the highest priority is serviced first. Upon return from the interrupt service routine, the next highest-level pending interrupt is serviced. If the VIS instruction is executed, but no interrupts are enabled and pending, the lowest-priority interrupt vector is used, and a jump is made to the corresponding address in the vector table. This is an unusual occurrence, and may be the result of an error. It can legitimately result from a change in the enable bits or pending flags prior to the execution of the VIS instruction, such as executing a single cycle instruction which clears an enable flag at the same time that the pending flag is set. It can also result, however, from inadvertent execution of the VIS command outside of the context of an interrupt. The default VIS interrupt vector can be useful for applications in which time critical interrupts can occur during the servicing of another interrupt. Rather than restoring the pro- TABLE 6. Interrupt Vector Table Arbitration Ranking Source Description INTR Instruction Vector Address (Note 17) (Hi-Low Byte) (1) Highest Software (2) Reserved 0yFE-0yFF (3) External G0 0yFA-0yFB (4) Timer T0 Underflow 0yF8-0yF9 (5) Timer T1 T1A/Underflow 0yF6-0yF7 (6) Timer T1 T1B 0yF4-0yF5 (7) MICROWIRE/PLUS BUSY Low 0yF2-0yF3 (8) Reserved (9) USART Receive 0yEE-0yEF (10) USART Transmit 0yEC-0yED (11) Timer T2 T2A/Underflow 0yEA-0yEB (12) Timer T2 T2B 0yE8-0yE9 (13) Timer T3 T2A/Underflow 0yE6-0yE7 (14) Timer T3 T3B 0yE4-0yE5 (15) Port L/Wakeup Port L Edge 0yE2-0yE3 (16) Lowest Default VIS Reserved 0yE0-0yE1 0yFC-0yFD 0yF0-0yF1 Note 17: y is a variable which represents the VIS block. VIS and the vector table must be located in the same 256-byte block except if VIS is located at the last address of a block. In this case, the table must be in the next block. www.national.com 36 remains unchanged. The new PC is therefore pointing to the vector of the active interrupt with the highest arbitration ranking. This vector is read from program memory and placed into the PC which is now pointed to the 1st instruction of the service routine of the active interrupt with the highest arbitration ranking. (Continued) 10.3.1 VIS Execution When the VIS instruction is executed it activates the arbitration logic. The arbitration logic generates an even number between E0 and FE (E0, E2, E4, E6 etc...) depending on which active interrupt has the highest arbitration ranking at the time of the 1st cycle of VIS is executed. For example, if the software trap interrupt is active, FE is generated. If the external interrupt is active and the software trap interrupt is not, then FA is generated and so forth. If the only active interrupt is software trap, than E0 is generated. This number replaces the lower byte of the PC. The upper byte of the PC Figure 26 illustrates the different steps performed by the VIS instruction. Figure 27 shows a flowchart for the VIS instruction. The non-maskable interrupt pending flag is cleared by the RPND (Reset Non-Maskable Pending Bit) instruction (under certain conditions) and upon RESET. 10131729 FIGURE 26. VIS Operation 37 www.national.com COP8SG Family 10.0 Interrupts COP8SG Family 10.0 Interrupts (Continued) 10131730 FIGURE 27. VIS Flowchart www.national.com 38 COP8SG Family 10.0 Interrupts (Continued) Programming Example: External Interrupt WAIT: PSW CNTRL RBIT RBIT SBIT SBIT SBIT JP . . . .=0FF VIS =00EF =00EE 0,PORTGC 0,PORTGD IEDG, CNTRL EXEN, PSW GIE, PSW WAIT ; ; ; ; ; G0 pin configured Hi-Z Ext interrupt polarity; falling edge Enable the external interrupt Set the GIE bit Wait for external interrupt ; The interrupt causes a ; branch to address 0FF ; The VIS causes a branch to ;interrupt vector table . . . .=01FA .ADDRW SERVICE ; Vector table (within 256 byte ; of VIS inst.) containing the ext ; interrupt service routine . . INT_EXIT: SERVICE: RETI . . RBIT . . . JP EXPND, PSW INT_EXIT ; Interrupt Service Routine ; Reset ext interrupt pend. bit ; Return, set the GIE bit 39 www.national.com COP8SG Family 10.0 Interrupts flag; upon return to the first Software Trap routine, the STPND flag will have the wrong state. This will allow maskable interrupts to be acknowledged during the servicing of the first Software Trap. To avoid problems such as this, the user program should contain the Software Trap routine to perform a recovery procedure rather than a return to normal execution. (Continued) 10.4 NON-MASKABLE INTERRUPT 10.4.1 Pending Flag There is a pending flag bit associated with the non-maskable interrupt, called STPND. This pending flag is not memorymapped and cannot be accessed directly by the software. The pending flag is reset to zero when a device Reset occurs. When the non-maskable interrupt occurs, the associated pending bit is set to 1. The interrupt service routine should contain an RPND instruction to reset the pending flag to zero. The RPND instruction always resets the STPND flag. Under normal conditions, the STPND flag is reset by a RPND instruction in the Software Trap service routine. If a programming error or hardware condition (brownout, power supply glitch, etc.) sets the STPND flag without providing a way for it to be cleared, all other interrupts will be locked out. To alleviate this condition, the user can use extra RPND instructions in the main program and in the WATCHDOG service routine (if present). There is no harm in executing extra RPND instructions in these parts of the program. 10.4.2 Software Trap The Software Trap is a special kind of non-maskable interrupt which occurs when the INTR instruction (used to acknowledge interrupts) is fetched from program memory and placed in the instruction register. This can happen in a variety of ways, usually because of an error condition. Some examples of causes are listed below. If the program counter incorrectly points to a memory location beyond the available program memory space, the nonexistent or unused memory location returns zeroes which is interpreted as the INTR instruction. If the stack is popped beyond the allowed limit (address 06F Hex), a 7FFF will be loaded into the PC, if this last location in program memory is unprogrammed or unavailable, a Software Trap will be triggered. A Software Trap can be triggered by a temporary hardware condition such as a brownout or power supply glitch. The Software Trap has the highest priority of all interrupts. When a Software Trap occurs, the STPND bit is set. The GIE bit is not affected and the pending bit (not accessible by the user) is used to inhibit other interrupts and to direct the program to the ST service routine with the VIS instruction. Nothing can interrupt a Software Trap service routine except for another Software Trap. The STPND can be reset only by the RPND instruction or a chip Reset. The Software Trap indicates an unusual or unknown error condition. Generally, returning to normal execution at the point where the Software Trap occurred cannot be done reliably. Therefore, the Software Trap service routine should reinitialize the stack pointer and perform a recovery procedure that restarts the software at some known point, similar to a device Reset, but not necessarily performing all the same functions as a device Reset. The routine must also execute the RPND instruction to reset the STPND flag. Otherwise, all other interrupts will be locked out. To the extent possible, the interrupt routine should record or indicate the context of the device so that the cause of the Software Trap can be determined. If the user wishes to return to normal execution from the point at which the Software Trap was triggered, the user must first execute RPND, followed by RETSK rather than RETI or RET. This is because the return address stored on the stack is the address of the INTR instruction that triggered the interrupt. The program must skip that instruction in order to proceed with the next one. Otherwise, an infinite loop of Software Traps and returns will occur. Programming a return to normal execution requires careful consideration. If the Software Trap routine is interrupted by another Software Trap, the RPND instruction in the service routine for the second Software Trap will reset the STPND www.national.com 10.5 PORT L INTERRUPTS Port L provides the user with an additional eight fully selectable, edge sensitive interrupts which are all vectored into the same service subroutine. The interrupt from Port L shares logic with the wake up circuitry. The register WKEN allows interrupts from Port L to be individually enabled or disabled. The register WKEDG specifies the trigger condition to be either a positive or a negative edge. Finally, the register WKPND latches in the pending trigger conditions. The GIE (Global Interrupt Enable) bit enables the interrupt function. A control flag, LPEN, functions as a global interrupt enable for Port L interrupts. Setting the LPEN flag will enable interrupts and vice versa. A separate global pending flag is not needed since the register WKPND is adequate. Since Port L is also used for waking the device out of the HALT or IDLE modes, the user can elect to exit the HALT or IDLE modes either with or without the interrupt enabled. If he elects to disable the interrupt, then the device will restart execution from the instruction immediately following the instruction that placed the microcontroller in the HALT or IDLE modes. In the other case, the device will first execute the interrupt service routine and then revert to normal operation. (See HALT MODE for clock option wakeup information.) 10.6 INTERRUPT SUMMARY The device uses the following types of interrupts, listed below in order of priority: 1. The Software Trap non-maskable interrupt, triggered by the INTR (00 opcode) instruction. The Software Trap is acknowledged immediately. This interrupt service routine can be interrupted only by another Software Trap. The Software Trap should end with two RPND instructions followed by a restart procedure. 2. Maskable interrupts, triggered by an on-chip peripheral block or an external device connected to the device. Under ordinary conditions, a maskable interrupt will not interrupt any other interrupt routine in progress. A maskable interrupt routine in progress can be interrupted by the non-maskable interrupt request. A maskable interrupt routine should end with an RETI instruction or, prior to restoring context, should return to execute the VIS instruction. This is particularly useful when exiting long interrupt service routiness if the time between interrupts is short. In this case the RETI instruction would only be executed when the default VIS routine is reached. 40 The WATCHDOG is enabled by bit 2 of the ECON register. When this ECON bit is 0, the WATCHDOG is enabled and pin G1 becomes the WATCHDOG output with a weak pullup. Each device contains a user selectable WATCHDOG and clock monitor. The following section is applicable only if WATCHDOG feature has been selected in the ECON register. The WATCHDOG is designed to detect the user program getting stuck in infinite loops resulting in loss of program control or "runaway" programs. The WATCHDOG logic contains two separate service windows. While the user programmable upper window selects the WATCHDOG service time, the lower window provides protection against an infinite program loop that contains the WATCHDOG service instruction. The Clock Monitor is used to detect the absence of a clock or a very slow clock below a specified rate on the CKI pin. The WATCHDOG consists of two independent logic blocks: WD UPPER and WD LOWER. WD UPPER establishes the upper limit on the service window and WD LOWER defines the lower limit of the service window. Servicing the WATCHDOG consists of writing a specific value to a WATCHDOG Service Register named WDSVR which is memory mapped in the RAM. This value is composed of three fields, consisting of a 2-bit Window Select, a 5-bit Key Data field, and the 1-bit Clock Monitor Select field. Table 7 shows the WDSVR register. The WATCHDOG and Clock Monitor are disabled during reset. The device comes out of reset with the WATCHDOG armed, the WATCHDOG Window Select bits (bits 6, 7 of the WDSVR Register) set, and the Clock Monitor bit (bit 0 of the WDSVR Register) enabled. Thus, a Clock Monitor error will occur after coming out of reset, if the instruction cycle clock frequency has not reached a minimum specified value, including the case where the oscillator fails to start. The WDSVR register can be written to only once after reset and the key data (bits 5 through 1 of the WDSVR Register) must match to be a valid write. This write to the WDSVR register involves two irrevocable choices: (i) the selection of the WATCHDOG service window (ii) enabling or disabling of the Clock Monitor. Hence, the first write to WDSVR Register involves selecting or deselecting the Clock Monitor, select the WATCHDOG service window and match the WATCHDOG key data. Subsequent writes to the WDSVR register will compare the value being written by the user to the WATCHDOG service window value and the key data (bits 7 through 1) in the WDSVR Register. Table 9 shows the sequence of events that can occur. The user must service the WATCHDOG at least once before the upper limit of the service window expires. The WATCHDOG may not be serviced more than once in every lower limit of the service window. The WATCHDOG has an output pin associated with it. This is the WDOUT pin, on pin 1 of the port G. WDOUT is active low and must be externally connected to the RESET pin or to some other external logic which handles WATCHDOG event. The WDOUT pin has a weak pullup in the inactive state. This pull-up is sufficient to serve as the connection to VCC for systems which use the internal Power On Reset. Upon triggering the WATCHDOG, the logic will pull the WDOUT (G1) pin low for an additional 16 tC-32 tC cycles after the signal level on WDOUT pin goes below the lower Schmitt trigger threshold. After this delay, the device will stop forcing the WDOUT output low. The WATCHDOG service window will restart when the WDOUT pin goes high. A WATCHDOG service while the WDOUT signal is active will be ignored. The state of the WDOUT pin is not guaranteed on reset, but if it powers up low then the WATCHDOG will time out and WDOUT will go high. The Clock Monitor forces the G1 pin low upon detecting a clock frequency error. The Clock Monitor error will continue until the clock frequency has reached the minimum specified value, after which the G1 output will go high following 16 tC-32 tC clock cycles. The Clock Monitor generates a continual Clock Monitor error if the oscillator fails to start, or fails to reach the minimum specified frequency. The specification for the Clock Monitor is as follows: 1/tC > 10 kHz -- No clock rejection. TABLE 7. WATCHDOG Service Register (WDSVR) Window Select Clock Monitor Key Data X X 0 1 1 0 0 Y 7 6 5 4 3 2 1 0 The lower limit of the service window is fixed at 2048 instruction cycles. Bits 7 and 6 of the WDSVR register allow the user to pick an upper limit of the service window. Table 8 shows the four possible combinations of lower and upper limits for the WATCHDOG service window. This flexibility in choosing the WATCHDOG service window prevents any undue burden on the user software. Bits 5, 4, 3, 2 and 1 of the WDSVR register represent the 5-bit Key Data field. The key data is fixed at 01100. Bit 0 of the WDSVR Register is the Clock Monitor Select bit. TABLE 8. WATCHDOG Service Window Select WDSVR WDSVR Clock Service Window Bit 7 Bit 6 Monitor (Lower-Upper Limits) 0 0 x 2048-8k tC Cycles 0 1 x 2048-16k tC Cycles 1 0 x 2048-32k tC Cycles 1 1 x 2048-64k tC Cycles x x 0 Clock Monitor Disabled x x 1 Clock Monitor Enabled 1/tC < 10 Hz -- Guaranteed clock rejection. 11.1 CLOCK MONITOR The Clock Monitor aboard the device can be selected or deselected under program control. The Clock Monitor is guaranteed not to reject the clock if the instruction cycle clock (1/tC) is greater or equal to 10 kHz. This equates to a clock input rate on CKI of greater or equal to 100 kHz. 41 www.national.com COP8SG Family 11.2 WATCHDOG/CLOCK MONITOR OPERATION 11.0 WATCHDOG/Clock Monitor COP8SG Family 11.0 WATCHDOG/Clock Monitor (Continued) TABLE 9. WATCHDOG Service Actions Key Window Clock Data Data Monitor Match Match Match Action Valid Service: Restart Service Window Don't Care Mismatch Don't Care Error: Generate WATCHDOG Output Mismatch Don't Care Don't Care Error: Generate WATCHDOG Output Don't Care Don't Care Mismatch Error: Generate WATCHDOG Output * 11.3 WATCHDOG AND CLOCK MONITOR SUMMARY The following salient points regarding the WATCHDOG and CLOCK MONITOR should be noted: * Both the WATCHDOG and CLOCK MONITOR detector circuits are inhibited during RESET. * Following RESET, the WATCHDOG and CLOCK MONITOR are both enabled, with the WATCHDOG having the maximum service window selected. * The WATCHDOG service window and CLOCK MONITOR enable/disable option can only be changed once, during the initial WATCHDOG service following RESET. * The initial WATCHDOG service must match the key data value in the WATCHDOG Service register WDSVR in order to avoid a WATCHDOG error. * Subsequent WATCHDOG services must match all three data fields in WDSVR in order to avoid WATCHDOG errors. * The correct key data value cannot be read from the WATCHDOG Service register WDSVR. Any attempt to read this key data value of 01100 from WDSVR will read as key data value of all 0's. * The WATCHDOG detector circuit is inhibited during both the HALT and IDLE modes. * The CLOCK MONITOR detector circuit is active during both the HALT and IDLE modes. Consequently, the device inadvertently entering the HALT mode will be detected as a CLOCK MONITOR error (provided that the CLOCK MONITOR enable option has been selected by the program). * With the single-pin R/C oscillator option selected and the CLKDLY bit reset, the WATCHDOG service window will resume following HALT mode from where it left off before entering the HALT mode. * With the crystal oscillator option selected, or with the single-pin R/C oscillator option selected and the CLKDLY bit set, the WATCHDOG service window will be set to its selected value from WDSVR following HALT. Consequently, the WATCHDOG should not be serviced for at least 2048 instruction cycles following HALT, but must be serviced within the selected window to avoid a WATCHDOG error. * * The IDLE timer T0 is not initialized with external RESET. * A hardware WATCHDOG service occurs just as the device exits the IDLE mode. Consequently, the WATCHDOG should not be serviced for at least 2048 instruction cycles following IDLE, but must be serviced within the selected window to avoid a WATCHDOG error. 11.4 DETECTION OF ILLEGAL CONDITIONS The device can detect various illegal conditions resulting from coding errors, transient noise, power supply voltage drops, runaway programs, etc. Reading of undefined ROM gets zeroes. The opcode for software interrupt is 00. If the program fetches instructions from undefined ROM, this will force a software interrupt, thus signaling that an illegal condition has occurred. The subroutine stack grows down for each call (jump to subroutine), interrupt, or PUSH, and grows up for each return or POP. The stack pointer is initialized to RAM location 06F Hex during reset. Consequently, if there are more returns than calls, the stack pointer will point to addresses 070 and 071 Hex (which are undefined RAM). Undefined RAM from addresses 070 to 07F (Segment 0), and all other segments (i.e., Segments 4 ... etc.) is read as all 1's, which in turn will cause the program to return to address 7FFF Hex. It is recommended that the user either leave this location unprogrammed or place an INTR instruction (all 0's) in this location to generate a software interrupt signaling an illegal condition. Thus, the chip can detect the following illegal conditions: 1. Executing from undefined ROM. 2. Over "POP"ing the stack by having more returns than calls. When the software interrupt occurs, the user can re-initialize the stack pointer and do a recovery procedure before restarting (this recovery program is probably similar to that following reset, but might not contain the same program initialization procedures). The recovery program should reset the software interrupt pending bit using the RPND instruction. 12.0 MICROWIRE/PLUS MICROWIRE/PLUS is a serial SPI compatible synchronous communications interface. The MICROWIRE/PLUS capability enables the device to interface with MICROWIRE/PLUS or SPI peripherals (i.e. A/D converters, display drivers, EEPROMs etc.) and with other microcontrollers which support the MICROWIRE/PLUS or SPI interface. It consists of an 8-bit serial shift register (SIO) with serial data input (SI), serial data output (SO) and serial shift clock (SK). Figure 28 shows a block diagram of the MICROWIRE/PLUS logic. The shift clock can be selected from either an internal source or an external source. Operating the MICROWIRE/PLUS The user can sync in to the IDLE counter cycle with an IDLE counter (T0) interrupt or by monitoring the T0PND flag. The T0PND flag is set whenever the twelfth bit of the IDLE counter toggles (every 4096 instruction cycles). The user is responsible for resetting the T0PND flag. www.national.com Following RESET, the initial WATCHDOG service (where the service window and the CLOCK MONITOR enable/ disable must be selected) may be programmed anywhere within the maximum service window (65,536 instruction cycles) initialized by RESET. Note that this initial WATCHDOG service may be programmed within the initial 2048 instruction cycles without causing a WATCHDOG error. 42 enabled, an interrupt is generated when eight data bits have been shifted. The device may enter the MICROWIRE/PLUS mode either as a Master or as a Slave. Figure 28 shows how two microcontroller devices and several peripherals may be interconnected using the MICROWIRE/PLUS arrangements. (Continued) arrangement with the internal clock source is called the Master mode of operation. Similarly, operating the MICROWIRE/PLUS arrangement with an external shift clock is called the Slave mode of operation. WARNING The CNTRL register is used to configure and control the MICROWIRE/PLUS mode. To use the MICROWIRE/PLUS, the MSEL bit in the CNTRL register is set to one. In the master mode, the SK clock rate is selected by the two bits, SL0 and SL1, in the CNTRL register. Table 10 details the different clock rates that may be selected. The SIO register should only be loaded when the SK clock is in the idle phase. Loading the SIO register while the SK clock is in the active phase, will result in undefined data in the SIO register. Setting the BUSY flag when the input SK clock is in the active phase while in the MICROWIRE/PLUS is in the slave mode may cause the current SK clock for the SIO shift register to be narrow. For safety, the BUSY flag should only be set when the input SK clock is in the idle phase. TABLE 10. MICROWIRE/PLUS Master Mode Clock Select SL1 SL0 SK Period 0 0 2 x tC 0 1 4 x tC 1 x 8 x tC 12.1.1 MICROWIRE/PLUS Master Mode Operation In the MICROWIRE/PLUS Master mode of operation the shift clock (SK) is generated internally. The MICROWIRE Master always initiates all data exchanges. The MSEL bit in the CNTRL register must be set to enable the SO and SK functions onto the G Port. The SO and SK pins must also be selected as outputs by setting appropriate bits in the Port G configuration register. In the slave mode, the shift clock stops after 8 clock pulses. Table 11 summarizes the bit settings required for Master mode of operation. Where tC is the instruction cycle clock 12.1 MICROWIRE/PLUS OPERATION Setting the BUSY bit in the PSW register causes the MICROWIRE/PLUS to start shifting the data. It gets reset when eight data bits have been shifted. The user may reset the BUSY bit by software to allow less than 8 bits to shift. If 10131732 FIGURE 28. MICROWIRE/PLUS Application 43 www.national.com COP8SG Family 12.0 MICROWIRE/PLUS COP8SG Family 12.0 MICROWIRE/PLUS The user must set the BUSY flag immediately upon entering the Slave mode. This ensures that all data bits sent by the Master is shifted properly. After eight clock pulses the BUSY flag is clear, the shift clock is stopped, and the sequence may be repeated. (Continued) 12.1.2 MICROWIRE/PLUS Slave Mode Operation In the MICROWIRE/PLUS Slave mode of operation the SK clock is generated by an external source. Setting the MSEL bit in the CNTRL register enables the SO and SK functions onto the G Port. The SK pin must be selected as an input and the SO pin is selected as an output pin by setting and resetting the appropriate bits in the Port G configuration register. Table 11 summarizes the settings required to enter the Slave mode of operation. 12.1.3 Alternate SK Phase Operation and SK Idle P The device allows either the normal SK clock or an alternate phase SK clock to shift data in and out of the SIO register. In both the modes the SK idle polarity can be either high or low. The polarity is selected by bit 5 of Port G data register. In the normal mode data is shifted in on the rising edge of the SK clock and the data is shifted out on the falling edge of the SK clock. In the alternate SK phase operation, data is shifted in on the falling edge of the SK clock and shifted out on the rising edge of the SK clock. Bit 6 of Port G configuration register selects the SK edge. A control flag, SKSEL, allows either the normal SK clock or the alternate SK clock to be selected. Resetting SKSEL causes the MICROWIRE/PLUS logic to be clocked from the normal SK signal. Setting the SKSEL flag selects the alternate SK clock. The SKSEL is mapped into the G6 configuration bit. The SKSEL flag will power up in the reset condition, selecting the normal SK signal. TABLE 11. MICROWIRE/PLUS Mode Settings This table assumes that the control flag MSEL is set. G4 (SO) G5 (SK) G4 G5 Config. Bit Config. Bit Fun. Fun. 1 1 SO Int. TRI- Operation MICROWIRE/PLUS SK Master Int. MICROWIRE/PLUS 0 1 STATE SK Master 1 0 SO Ext. MICROWIRE/PLUS SK Slave 0 0 TRI- Ext. MICROWIRE/PLUS STATE SK Slave TABLE 12. MICROWIRE/PLUS Shift Clock Polarity and Sample/Shift Phase Port G SK Phase G6 (SKSEL) Config. Bit G5 Data Bit SO Clocked Out On: SI Sampled On: SK Idle Phase Normal 0 0 SK Falling Edge SK Rising Edge Low Alternate 1 0 SK Rising Edge SK Falling Edge Low Alternate 0 1 SK Rising Edge SK Falling Edge High Normal 1 1 SK Falling Edge SK Rising Edge High 10131733 FIGURE 29. MICROWIRE/PLUS SPI Mode Interface Timing, Normal SK Mode, SK Idle Phase being Low www.national.com 44 COP8SG Family 12.0 MICROWIRE/PLUS (Continued) 10131734 FIGURE 30. MICROWIRE/PLUS SPI Mode Interface Timing, Alternate SK Mode, SK Idle Phase being Low 10131735 FIGURE 31. MICROWIRE/PLUS SPI Mode Interface Timing, Normal SK Mode, SK Idle Phase being High 10131731 FIGURE 32. MICROWIRE/PLUS SPI Mode Interface Timing, Alternate SK Mode, SK Idle Phase being High 45 www.national.com COP8SG Family 13.0 Memory Map Address S/ADD REG All RAM, ports and registers (except A and PC) are mapped into data memory address space. Address Contents Contents xxC9 MIWU Enable Register (Reg:WKEN) xxCA MIWU Pending Register (Reg:WKPND) xxCB to xxCF Reserved 0000 to 006F On-Chip RAM bytes (112 bytes) xxD0 Port L Data Register 0070 to 007F Unused RAM Address Space (Reads As All Ones) xxD1 Port L Configuration Register xxD2 Port L Input Pins (Read Only) xx80 to xx93 Unused RAM Address Space (Reads Undefined Data) xxD3 Reserved for Port L xxD4 Port G Data Register xx94 Port F data register, PORTFD xxD5 Port G Configuration Register xx95 Port F configuration register, PORTFC xxD6 Port G Input Pins (Read Only) xx96 Port F input pins (read only), PORTFP xxD7 xx97 to xxAF Unused address space (Reads Undefined Data) Port I Input Pins (Read Only) (Actually reads Port F input pins) xxD8 Port C Data Register xxB0 Timer T3 Lower Byte xxD9 Port C Configuration Register xxB1 Timer T3 Upper Byte xxDA Port C Input Pins (Read Only) xxB2 Timer T3 Autoload Register T3RA Lower Byte xxDB Reserved for Port C xxDC Port D xxB3 Timer T3 Autoload Register T3RA Upper Byte xxDD to xxDF Reserved for Port D xxE0 to xxE5 Reserved for EE Control Registers xxB4 Timer T3 Autoload Register T3RB Lower Byte xxE6 Timer T1 Autoload Register T1RB Lower Byte xxB5 Timer T3 Autoload Register T3RB Upper Byte xxE7 Timer T1 Autoload Register T1RB Upper Byte xxB6 Timer T3 Control Register xxE8 ICNTRL Register xxB7 Comparator Select Register (Reg:CMPSL) xxE9 MICROWIRE/PLUS Shift Register xxB8 UART Transmit Buffer (Reg:TBUF) xxEA Timer T1 Lower Byte xxB9 UART Receive Buffer (Reg:RBUF) xxEB Timer T1 Upper Byte xxBA UART Control and Status Register (Reg:ENU) xxEC Timer T1 Autoload Register T1RA Lower Byte xxBB UART Receive Control and Status Register (Reg:ENUR) xxED Timer T1 Autoload Register T1RA Upper Byte xxBC UART Interrupt and Clock Source Register (Reg:ENUI) xxEE CNTRL Control Register S/ADD REG xxBD UART Baud Register (Reg:BAUD) xxBE UART Prescale Select Register (Reg:PSR) xxBF Reserved for UART xxC0 Timer T2 Lower Byte xxC1 Timer T2 Upper Byte xxC2 Timer T2 Autoload Register T2RA Lower Byte xxC3 Timer T2 Autoload Register T2RA Upper Byte xxC4 Timer T2 Autoload Register T2RB Lower Byte xxC5 Timer T2 Autoload Register T2RB Upper Byte xxC6 Timer T2 Control Register xxC7 WATCHDOG Service Register (Reg:WDSVR) xxC8 MIWU Edge Select Register (Reg:WKEDG) www.national.com xxEF PSW Register xxF0 to FB On-Chip RAM Mapped as Registers xxFC X Register xxFD SP Register xxFE B Register xxFF S Register 0100-017F On-Chip 128 RAM Bytes 0200-027F On-Chip 128 RAM Bytes (Reads as undefined data on COP8SGE) 0300-037F On-Chip 128 RAM Bytes (Reads as undefined data on COP8SGE) Note: Reading memory locations 0070H-007FH (Segment 0) will return all ones. Reading unused memory locations 0080H-0093H (Segment 0) will return undefined data. Reading memory locations from other Segments (i.e., Segment 4, Segment 5, ... etc.) will return undefined data. 46 The available addressing modes are: 14.1 INTRODUCTION * * * This section defines the instruction set of the COP8 Family members. It contains information about the instruction set features, addressing modes and types. Mostly single-byte opcode instructions minimize program size. * One instruction cycle for the majority of single-byte instructions to minimize program execution time. * Many single-byte, multiple function instructions such as DRSZ. * Three memory mapped pointers: two for register indirect addressing, and one for the software stack. * Sixteen memory mapped registers that allow an optimized implementation of certain instructions. * * * Register B or X Indirect Register B or X Indirect with Post-Incrementing/ Decrementing * Immediate * Immediate Short * Indirect from Program Memory The addressing modes are described below. Each description includes an example of an assembly language instruction using the described addressing mode. Direct. The memory address is specified directly as a byte in the instruction. In assembly language, the direct address is written as a numerical value (or a label that has been defined elsewhere in the program as a numerical value). Example: Load Accumulator Memory Direct LD A,05 14.2 INSTRUCTION FEATURES The strength of the instruction set is based on the following features: * Direct Ability to set, reset, and test any individual bit in data memory address space, including the memory-mapped I/O ports and registers. Reg/Data Contents Contents Memory Before After Accumulator XX Hex A6 Hex Memory Location A6 Hex A6 Hex 0005 Hex Register-Indirect LOAD and EXCHANGE instructions with optional automatic post-incrementing or decrementing of the register pointer. This allows for greater efficiency (both in cycle time and program code) in loading, walking across and processing fields in data memory. Register B or X Indirect. The memory address is specified by the contents of the B Register or X register (pointer register). In assembly language, the notation [B] or [X] specifies which register serves as the pointer. Example: Exchange Memory with Accumulator, B Indirect X A,[B] Unique instructions to optimize program size and throughput efficiency. Some of these instructions are DRSZ, IFBNE, DCOR, RETSK, VIS and RRC. 14.3 ADDRESSING MODES The instruction set offers a variety of methods for specifying memory addresses. Each method is called an addressing mode. These modes are classified into two categories: operand addressing modes and transfer-of-control addressing modes. Operand addressing modes are the various methods of specifying an address for accessing (reading or writing) data. Transfer-of-control addressing modes are used in conjunction with jump instructions to control the execution sequence of the software program. Reg/Data Contents Memory Before Contents After Accumulator 01 Hex 87 Hex Memory Location 87 Hex 01 Hex 05 Hex 05 Hex 0005 Hex B Pointer Register B or X Indirect with Post-Incrementing/ Decrementing. The relevant memory address is specified by the contents of the B Register or X register (pointer register). The pointer register is automatically incremented or decremented after execution, allowing easy manipulation of memory blocks with software loops. In assembly language, the notation [B+], [B-], [X+], or [X-] specifies which register serves as the pointer, and whether the pointer is to be incremented or decremented. Example: Exchange Memory with Accumulator, B Indirect with Post-Increment X A,[B+] 14.3.1 Operand Addressing Modes The operand of an instruction specifies what memory location is to be affected by that instruction. Several different operand addressing modes are available, allowing memory locations to be specified in a variety of ways. An instruction can specify an address directly by supplying the specific address, or indirectly by specifying a register pointer. The contents of the register (or in some cases, two registers) point to the desired memory location. In the immediate mode, the data byte to be used is contained in the instruction itself. Each addressing mode has its own advantages and disadvantages with respect to flexibility, execution speed, and program compactness. Not all modes are available with all instructions. The Load (LD) instruction offers the largest number of addressing modes. Reg/Data Contents Contents Memory Before After Accumulator 03 Hex 62 Hex Memory Location 62 Hex 03 Hex 05 Hex 06 Hex 0005 Hex B Pointer Intermediate. The data for the operation follows the instruction opcode in program memory. In assembly language, the number sign character (#) indicates an immediate operand. 47 www.national.com COP8SG Family 14.0 Instruction Set COP8SG Family 14.0 Instruction Set * Jump Indirect The transfer-of-control addressing modes are described below. Each description includes an example of a Jump instruction using a particular addressing mode, and the effect on the Program Counter bytes of executing that instruction. Jump Relative. In this 1-byte instruction, six bits of the instruction opcode specify the distance of the jump from the current program memory location. The distance of the jump can range from -31 to +32. A JP+1 instruction is not allowed. The programmer should use a NOP instead. Example: Jump Relative JP 0A (Continued) Example: Load Accumulator Immediate LD A,#05 Reg/Data Contents Memory Before Contents After Accumulator XX Hex 05 Hex Immediate Short. This is a special case of an immediate instruction. In the "Load B immediate" instruction, the 4-bit immediate value in the instruction is loaded into the lower nibble of the B register. The upper nibble of the B register is reset to 0000 binary. Example: Load B Register Immediate Short LD B,#7 Reg/Data Contents Contents Memory Before After B Pointer 12 Hex 07 Hex Reg Contents Contents Memory Before After PCU 04 Hex 04 Hex PCL 35 Hex 36 Hex Accumulator 1F Hex 25 Hex Memory Location 25 Hex 25 Hex After PCU 02 Hex 02 Hex PCL 05 Hex 0F Hex Reg Contents Contents Before After PCU 0C Hex 01 Hex PCL 77 Hex 25 Hex Jump Absolute Long. In this 3-byte instruction, 15 bits of the instruction opcode specify the new contents of the Program Counter. Example: Jump Absolute Long JMP 03625 041F Hex 14.3.2 Tranfer-of-Control Addressing Modes Program instructions are usually executed in sequential order. However, Jump instructions can be used to change the normal execution sequence. Several transfer-of-control addressing modes are available to specify jump addresses. A change in program flow requires a non-incremental change in the Program Counter contents. The Program Counter consists of two bytes, designated the upper byte (PCU) and lower byte (PCL). The most significant bit of PCU is not used, leaving 15 bits to address the program memory. Different addressing modes are used to specify the new address for the Program Counter. The choice of addressing mode depends primarily on the distance of the jump. Farther jumps sometimes require more instruction bytes in order to completely specify the new Program Counter contents. The available transfer-of-control addressing modes are: * * * Contents Before Jump Absolute. In this 2-byte instruction, 12 bits of the instruction opcode specify the new contents of the Program Counter. The upper three bits of the Program Counter remain unchanged, restricting the new Program Counter address to the same 4 kbyte address space as the current instruction. (This restriction is relevant only in devices using more than one 4 kbyte program memory space.) Example: Jump Absolute JMP 0125 Indirect from Program Memory. This is a special case of an indirect instruction that allows access to data tables stored in program memory. In the "Load Accumulator Indirect" (LAID) instruction, the upper and lower bytes of the Program Counter (PCU and PCL) are used temporarily as a pointer to program memory. For purposes of accessing program memory, the contents of the Accumulator and PCL are exchanged. The data pointed to by the Program Counter is loaded into the Accumulator, and simultaneously, the original contents of PCL are restored so that the program can resume normal execution. Example: Load Accumulator Indirect LAID Reg/Data Contents Reg/ Contents Memory Before Contents After PCU 42 Hex 36 Hex PCL 36 Hex 25 Hex Jump Indirect. In this 1-byte instruction, the lower byte of the jump address is obtained from a table stored in program memory, with the Accumulator serving as the low order byte of a pointer into program memory. For purposes of accessing program memory, the contents of the Accumulator are written to PCL (temporarily). The data pointed to by the Program Counter (PCH/PCL) is loaded into PCL, while PCH remains unchanged. Example: Jump Indirect JID Reg/ Contents Contents Memory Before After PCU 01 Hex 01 Hex Jump Relative PCL C4 Hex 32 Hex Jump Absolute Accumulator 26 Hex 26 Hex Memory Jump Absolute Long www.national.com 48 Reg/ 14.4.3 Load and Exchange Instructions (Continued) Contents The load and exchange instructions write byte values in registers or memory. The addressing mode determines the source of the data. Contents Memory Before After Location 32 Hex 32 Hex Load (LD) Load Accumulator Indirect (LAID) 0126 Hex Exchange (X) The VIS instruction is a special case of the Indirect Transfer of Control addressing mode, where the double-byte vector associated with the interrupt is transferred from adjacent addresses in program memory into the Program Counter in order to jump to the associated interrupt service routine. 14.4.4 Logical Instructions The logical instructions perform the operations AND, OR, and XOR (Exclusive OR). Other logical operations can be performed by combining these basic operations. For example, complementing is accomplished by exclusiveORing the Accumulator with FF Hex. Logical AND (AND) Logical OR (OR) Exclusive OR (XOR) 14.4 INSTRUCTION TYPES The instruction set contains a wide variety of instructions. The available instructions are listed below, organized into related groups. Some instructions test a condition and skip the next instruction if the condition is not true. Skipped instructions are executed as no-operation (NOP) instructions. 14.4.5 Accumulator Bit Manipulation Instructions The Accumulator bit manipulation instructions allow the user to shift the Accumulator bits and to swap its two nibbles. Rotate Right Through Carry (RRC) Rotate Left Through Carry (RLC) Swap Nibbles of Accumulator (SWAP) 14.4.1 Arithmetic Instructions The arithmetic instructions perform binary arithmetic such as addition and subtraction, with or without the Carry bit. Add (ADD) Add with Carry (ADC) Subtract (SUB) Subtract with Carry (SUBC) Increment (INC) Decrement (DEC) Decimal Correct (DCOR) Clear Accumulator (CLR) Set Carry (SC) Reset Carry (RC) 14.4.6 Stack Control Instructions Push Data onto Stack (PUSH) Pop Data off of Stack (POP) 14.4.7 Memory Bit Manipulation Instructions The memory bit manipulation instructions allow the user to set and reset individual bits in memory. Set Bit (SBIT) Reset Bit (RBIT) Reset Pending Bit (RPND) 14.4.2 Transfer-of-Control Instructions The transfer-of-control instructions change the usual sequential program flow by altering the contents of the Program Counter. The Jump to Subroutine instructions save the Program Counter contents on the stack before jumping; the Return instructions pop the top of the stack back into the Program Counter. Jump Relative (JP) Jump Absolute (JMP) Jump Absolute Long (JMPL) Jump Indirect (JID) Jump to Subroutine (JSR) Jump to Subroutine Long (JSRL) Return from Subroutine (RET) Return from Subroutine and Skip (RETSK) Return from Interrupt (RETI) Software Trap Interrupt (INTR) Vector Interrupt Select (VIS) 14.4.8 Conditional Instructions The conditional instruction test a condition. If the condition is true, the next instruction is executed in the normal manner; if the condition is false, the next instruction is skipped. If Equal (IFEQ) If Not Equal (IFNE) If Greater Than (IFGT) If Carry (IFC) If Not Carry (IFNC) If Bit (IFBIT) If B Pointer Not Equal (IFBNE) And Skip if Zero (ANDSZ) Decrement Register and Skip if Zero (DRSZ) 14.4.9 No-Operation Instruction The no-operation instruction does nothing, except to occupy space in the program memory and time in execution. No-Operation (NOP) Note: The VIS is a special case of the Indirect Transfer of Control addressing mode, where the double byte vector associated with the interrupt is transferred from adjacent addresses in the program memory into the program counter (PC) in order to jump to the associated interrupt service routine. 49 www.national.com COP8SG Family 14.0 Instruction Set COP8SG Family 14.0 Instruction Set (Continued) Registers 14.5 REGISTER AND SYMBOL DEFINITION VU Interrupt Vector Upper Byte The following abbreviations represent the nomenclature used in the instruction description and the COP8 cross-assembler. VL Interrupt Vector Lower Byte [B] Memory Indirectly Addressed by B Register Registers [X] Memory Indirectly Addressed by X Register Symbols A 8-Bit Accumulator Register MD Direct Addressed Memory B 8-Bit Address Register Mem Direct Addressed Memory or [B] X 8-Bit Address Register Meml SP 8-Bit Stack Pointer Register Direct Addressed Memory or [B] or Immediate Data PC 15-Bit Program Counter Register Imm 8-Bit Immediate Data PU Upper 7 Bits of PC Reg PL Lower 8 Bits of PC Register Memory: Addresses F0 to FF (Includes B, X and SP) C 1 Bit of PSW Register for Carry 1 Bit of PSW Register for Half Carry Bit Bit Number (0 to 7) HC GIE 1 Bit of PSW Register for Global Interrupt Enable Exchanged with Loaded with 14.6 INSTRUCTION SET SUMMARY ADD A,Meml ADD ADC A,Meml ADD with Carry SUBC A,Meml Subtract with Carry A A + Meml A A + Meml + C, C Carry, HC Half Carry A A - MemI + C, C Carry, HC Half Carry AND A,Meml Logical AND A A and Meml ANDSZ A,Imm Logical AND Immed., Skip if Zero OR A,Meml Logical OR Skip next if (A and Imm) = 0 A A or Meml XOR A,Meml Logical EXclusive OR A A xor Meml IFEQ MD,Imm IF EQual Compare MD and Imm, Do next if MD = Imm Compare A and Meml, Do next if A = Meml Compare A and Meml, Do next if A Meml IFEQ A,Meml IF EQual IFNE A,Meml IF Not Equal IFGT A,Meml IF Greater Than If B Not Equal Compare A and Meml, Do next if A > Meml Do next if lower 4 bits of B Imm IFBNE # DRSZ Reg Decrement Reg., Skip if Zero Reg Reg - 1, Skip if Reg = 0 SBIT #,Mem Set BIT 1 to bit, Mem (bit = 0 to 7 immediate) RBIT #,Mem Reset BIT 0 to bit, Mem IFBIT #,Mem IF BIT If bit #, A or Mem is true do next instruction Reset PeNDing Flag Reset Software Interrupt Pending Flag RPND X A,Mem EXchange A with Memory AMem X A,[X] EXchange A with Memory [X] LD A,Meml LoaD A with Memory A[X] A Meml LD A,[X] LoaD A with Memory [X] LD B,Imm LoaD B with Immed. LD Mem,Imm LoaD Memory Immed. LD Reg,Imm LoaD Register Memory Immed. X A, [B ] EXchange A with Memory [B] X A, [X ] EXchange A with Memory [X] LD A, [B ] LoaD A with Memory [B] LD A, [X ] LoaD A with Memory [X] LD [B ],Imm LoaD Memory [B] Immed. A[X], (XX 1) [B]Imm, (B B 1) CLR A CLeaR A A0 www.national.com A [X] B Imm Mem Imm Reg Imm A[B], (B B 1) A[X], (X X 1) A[B], (BB 1) 50 (Continued) INC A INCrement A DEC A DECrement A LAID AA + 1 AA - 1 A ROM (PU,A) Load A InDirect from ROM DCOR A Decimal CORrect A RRC A Rotate A Right thru C A BCD correction of A (follows ADC, SUBC) C A7 ... A0 C RLC A Rotate A Left thru C C A7 ... A0 C, HC A0 SWAP A SWAP nibbles of A A7...A4A3...A0 C 1, HC 1 SC Set C RC Reset C C0, HC 0 IFC IF C IF C is true, do next instruction IFNC IF Not C If C is not true, do next instruction SP SP + 1, A[SP] POP A POP the stack into A PUSH A PUSH A onto the stack VIS [SP] A, SP SP - 1 PU [VU], PL [VL] Vector to Interrupt Service Routine JMPL Addr. Jump absolute Long JMP Addr. Jump absolute JP Disp. Jump relative short JSRL Addr. Jump SubRoutine Long JSR Addr. Jump SubRoutine PCii (ii = 15 bits, 0 to 32k) PC9...0 i (i = 12 bits) PCPC + r (r is -31 to +32, except 1) [SP] PL, [SP-1] PU,SP-2, PC ii [SP]PL, [SP-1] PU,SP-2, PC9...0 i PL ROM (PU,A) JID Jump InDirect RET RETurn from subroutine RETSK RETurn and SKip SP + 2, PL [SP], PU [SP-1] SP + 2, PL[SP],PU[SP-1], RETI RETurn from Interrupt skip next instruction SP + 2, PL [SP],PU[SP-1],GIE 1 INTR Generate an Interrupt NOP No OPeration [SP] PL, [SP-1] PU, SP-2, PC 0FF PCPC + 1 51 www.national.com COP8SG Family 14.0 Instruction Set COP8SG Family 14.0 Instruction Set Instructions Using A & C (Continued) 14.7 INSTRUCTION EXECUTION TIME CLRA Most instructions are single byte (with immediate addressing mode instructions taking two bytes). INCA 1/1 DECA 1/1 Most single byte instructions take one cycle time to execute. LAID 1/3 Skipped instructions require x number of cycles to be skipped, where x equals the number of bytes in the skipped instruction opcode. See the BYTES and CYCLES per INSTRUCTION table for details. Bytes and Cycles per Instruction The following table shows the number of bytes and cycles for each instruction in the format of byte/cycle. Arithmetic and Logic Instructions DCORA 1/1 RRCA 1/1 RLCA 1/1 SWAPA 1/1 SC 1/1 RC 1/1 IFC 1/1 IFNC 1/1 [B] Direct Immed. 1/1 PUSHA 1/3 1/3 ADD 1/1 3/4 2/2 POPA ADC 1/1 3/4 2/2 SUBC 1/1 3/4 2/2 ANDSZ 2/2 Transfer of Control Instructions AND 1/1 3/4 2/2 JMPL 3/4 OR 1/1 3/4 2/2 JMP 2/3 XOR 1/1 3/4 2/2 JP 1/3 IFEQ 1/1 3/4 2/2 JSRL 3/5 IFGT 1/1 3/4 2/2 JSR 2/5 IFBNE 1/1 JID 1/3 1/3 DRSZ VIS 1/5 SBIT 1/1 3/4 RET 1/5 RBIT 1/1 3/4 RETSK 1/5 IFBIT 1/1 3/4 RETI 1/5 INTR 1/7 NOP 1/1 RPND 1/1 Memory Transfer Instructions Register Direct Immed. Indirect [B] [X] X A, (Note 18) 1/1 1/3 2/3 LD A, (Note 18) 1/1 1/3 2/3 2/2 [B+, B-] [X+, X-] 1/2 1/3 1/2 1/3 LD B, Imm 1/1 (If B < 16) LD B, Imm 2/2 (If B > 15) LD Mem, Imm Note 18: = Register Indirect Auto Incr. & Decr. 2/2 3/3 LD Reg, Imm 2/3 IFEQ MD, Imm 3/3 2/2 > Memory location addressed by B or X or directly. www.national.com 52 JP-19 JP-18 JP-17 JP-3 JP-2 JP-1 Where, JP-16 JP-20 JP-4 JP-0 JP-21 JP-25 JP-9 JP-5 JP-26 JP-10 JP-22 JP-27 JP-11 JP-6 JP-28 JP-12 JP-23 JP-29 JP-13 JP-7 JP-30 JP-14 JP-24 JP-31 JP-15 JP-8 E F * RRCA B DRSZ 0FF DRSZ 0FE DRSZ 0FD DRSZ 0FC DRSZ 0FB DRSZ 0FA DRSZ 0F9 DRSZ 0F8 DRSZ 0F7 DRSZ 0F6 DRSZ 0F5 DRSZ 0F4 * LD A,[B] IFBIT 6,[B] IFBIT 5,[B] AND A,[B] XOR A,[B] IFBIT 4,[B] IFBIT 3,[B] IFBIT 2,[B] IFBIT 1,[B] IFBIT 0,[B] 7 X A,Md LD [B-],#i LD [B+],#i IFNE A,#i LD A,#i POPA DECA INCA IFNC IFC LD B,#i LD [B],#i RETI RET SBIT 7,[B] SBIT 6,[B] SBIT 5,[B] SBIT 4,[B] SBIT 3,[B] SBIT 2,[B] SBIT 1,[B] SBIT 0,[B] 5 LD B,#00 LD B,#01 LD B,#02 LD B,#03 LD B,#04 LD B,#05 LD B,#06 LD B,#07 LD B,#08 LD B,#09 LD B,#0A LD B,#0B LD B,#0C LD B,#0D LD B,#0E LD B,#0F * is an unused opcode RBIT 7,[B] RBIT 6,[B] RBIT 5,[B] RBIT 4,[B] RBIT 3,[B] RBIT 2,[B] RBIT 1,[B] RBIT 0,[B] PUSHA DCORA SWAPA CLRA * * * ANDSZ A, #i 6 Upper Nibble ADD A,[B] IFGT A,[B] IFEQ A,[B] SUBC A,[B] ADC A,[B] 8 OR A,#i OR A,[B] IFBIT 7,[B] XOR A,#i AND A,#i ADD A,#i IFGT A,#i IFEQ A,#i SUBC A, #i ADC A,#i 9 JSRL LD A,Md RETSK JMPL LD A,[B-] LD A,[B+] IFEQ Md,#i RLCA * X A,[B] JID LAID X A,[B-] X A,[B+] SC RC A 14.8 OPCODE TABLE Md is a directly addressed memory location * LD A,[X] DIR LD Md,#i LD A,[X-] LD A,[X+] IFNE A,[B] NOP * X A,[X] RPND VIS DRSZ 0F3 X A,[X-] DRSZ 0F2 X A,[X+] DRSZ 0F1 DRSZ 0F0 C (Continued) i is the immediate data LD 0FF, #i LD 0FE, #i LD 0FD, #i LD 0FC, #i LD 0FB, #i LD 0FA, #i LD 0F9, #i LD 0F8, #i LD 0F7, #i LD 0F6, #i LD 0F5, #i LD 0F4, #i LD 0F3, #i LD 0F2, #i LD 0F1, #i LD 0F0, #i D 14.0 Instruction Set 4 3 JSR xF00-xFFF JSR xE00-xEFF JSR xD00-xDFF JSR xC00-xCFF JSR xB00-xBFF JSR xA00-xAFF JSR x900-x9FF JSR x800-x8FF JSR x700-x7FF JSR x600-x6FF JSR x500-x5FF JSR x400-x4FF JSR x300-x3FF JSR x200-x2FF JSR x100-x1FF JSR x000-x0FF 2 JMP xF00-xFFF JMP xE00-xEFF JMP xD00-xDFF JMP xC00-xCFF JMP xB00-xBFF JMP xA00-xAFF JMP x900-x9FF JMP x800-x8FF JMP x700-x7FF JMP x600-x6FF JMP x500-x5FF JMP x400-x4FF JMP x300-x3FF JMP x200-x2FF JMP x100-x1FF JMP x000-x0FF The opcode 60 Hex is also the opcode for IFBIT #i,A IFBNE 0F IFBNE 0E IFBNE 0D IFBNE 0C IFBNE 0B IFBNE 0A IFBNE 9 IFBNE 8 IFBNE 7 IFBNE 6 IFBNE 5 IFBNE 4 IFBNE 3 IFBNE 2 IFBNE 1 IFBNE 0 1 0 JP+9 JP+8 JP+7 JP+6 JP+5 JP+4 JP+3 JP+2 INTR 9 8 7 6 5 4 3 2 1 0 JP+32 JP+16 F JP+31 JP+15 E JP+30 JP+14 D JP+29 JP+13 C JP+28 JP+12 B JP+27 JP+11 A JP+26 JP+10 JP+25 JP+24 JP+23 JP+22 JP+21 JP+20 JP+19 JP+18 JP+17 Lower Nibble COP8SG Family 53 www.national.com COP8SG Family www.national.com 54 See Section 5.5 ECON (CONFIGURATION) REGISTER. 16.0 COP8 Tools Overview National is engaged with an international community of independent 3rd party vendors who provide hardware and software development tool support. Through National's interaction and guidance, these tools cooperate to form a choice of tools that fits each developer's needs. This section provides a summary of the tool and development kits currently available. Up-to-date information, selection guides, free tools, demos, updates, and purchase information can be obtained at our web site at: www.national.com/cop8. COP8 Development Productivity Tools * COP8-UTILS: COP8 assembly code examples, device drivers, and utilities to speed up code development. (Included with COP8-NSDEV and COP8-NSEVAL.) COP8 Hardware Debug Tools COP8-NSEVAL: Software Evaluation package for Windows. A fully integrated evaluation environment for COP8. Includes WCOP8 IDE evaluation version (Integrated Development Environment), COP8-NSASM (Full COP8 Assembler), COP8-MLSIM (COP8 Instruction Level Simulator), COP8C Compiler Demo, DriveWayTM COP8 Device-Driver-Builder Demo, Manuals, Applications Software, and other COP8 technical information. * COP8-EM-xx: Metalink COP8 Emulation Module for OTP/ROM COP8 Families. Windows based development and real-time in-circuit emulation tool, with 100 frame trace, 32k s/w breaks, Enhanced User Interface, MetaLink Debugger. Includes COP8-NSDEV, power supply, DIP emulation cables. * COP8-DM-xx: Metalink COP8 Debug Module for OTP/ROM COP8 Families. Windows based development and real-time in-circuit emulation tool, with 100 frame trace, 32k s/w breaks, Basic User Interface, MetaLink Debugger, and COP8 OTP Programmer with sockets. Includes COP8-NSDEV, power supply, DIP and/or SMD emulation cables and adapters. * COP8-REF-xx: Reference Designs for COP8 Families. Realtime hardware environment with a variety of functions for demonstrating the various capabilities and features of specific COP8 device families. Run Win 95 demo reference software and exercise specific device capabilities. COP8 Starter Kits and Hardware Target Solutions * COP8-IM: MetaLink iceMASTER (R) for OTP/ROM COP8 devices. Windows based, full featured real-time in-circuit emulator, with 4k trace, 32k s/w breaks, and MetaLink Windows Debugger. Includes COP8-NSDEV and power supply. Package-specific probes and surface mount adaptors are ordered separately. (Add COP8-PM and adapters for OTP programming.) COP8 Development and OTP Programming Tools * COP8-EVAL-xxx: A variety of Multifunction Evaluation, Design Test, and Target Boards for COP8 Families. Realtime target design environments with a selection of peripherals and features including multi I/O, LCD display, keyboard, A/D, D/A, EEPROM, USART, LEDs, and bread-board area. Quickly design, test, and implement a custom target system (some target boards are standalone, and ready for mounting into a standard enclosure), or just evaluate and test your code. COP8 Software Development Languages and Integrated Environments * * DriveWay-COP8: Aisys Corporation - COP8 Peripherals Code Generation tool. Automatically generates tested and documented C or Assembly source code modules containing I/O drivers and interrupt handlers for each on-chip peripheral. Application specific code can be inserted for customization using the integrated editor. * 16.1 SUMMARY OF TOOLS COP8 Evaluation Software and Reference Designs * EWCOP8, EWCOP8-M, EWCOP8-BL: IAR - ANSI C-Compiler and Embedded Workbench. (M version includes MetaLink debugger support) (BL version: 4k code limit; no FP). A fully integrated Win32 IDE, ANSI C-Compiler, macro assembler, editor, linker, librarian, and C-Spy high-level simulator/debugger. COP8-NSDEV: National's COP8 Software Development package for Windows on CD. A fully Integrated Development Environment for COP8. Includes a fully licensed WCOP8 IDE, COP8-NSASM. Plus Manuals, Applications Software, and other COP8 technical information. COP8C: ByteCraft - C Cross-Compiler and Code Development System. Includes BCLIDE (Integrated Development Environment) for Win32, editor, optimizing C CrossCompiler, macro cross assembler, BC-Linker, and MetaLinktools support. (DOS/SUN versions available. 55 * COP8-PM: COP8 Development Programming Module. Windows programming tool for COP8 OTP/Flash Families. Includes 40 DIP programming socket, control software, RS232 cable, and power supply. (Programming adapters are extra.) * Development: Metalink's Debug Module includes development device programming capability for COP8 devices. Many other third-party programmers are approved for development and engineering use. * Production: Third-party programmers and automatic handling equipment cover needs from engineering prototype and pilot production, to full production environments. * Factory Programming: Factory programming available for high-volume requirements. www.national.com COP8SG Family * 15.0 Mask Options COP8SG Family 16.0 COP8 Tools Overview (Continued) 16.2 TOOLS ORDERING NUMBERS FOR THE COP8SGx FAMILY DEVICES The COP8-IM/400 ICE can be used for emulation with the limitation of 10 MHz emulation speed maximum. For full speed COP8SGx emulation, use the 15 MHz COP8-DM-SG or COP8-EM-SG. Note: The following order numbers apply to the COP8 devices in this datasheet only. Vendor Tools Order Number Cost Notes COP8-NSEVAL COP8-NSEVAL VL COP8-REF COP8-REF-SG VL Order from web site COP8-EVAL COP8-EVAL-COB1 VL Order from web site COP8-NSDEV COP8-NSDEV VL Included in EM. Order CD from web site COP8-EM COP8-EM-SG M Included p/s, 28/40 pin DIP target cable, manuals, software EM Target Cables and Converters COP8-EMC-44P VL 44 PLCC Target Cable COP8-EMC-28CSP L 28 CSP Target Cable COP8-EMA-xxSO L DIP to SOIC Cable Converter COP8-EMA-44QFP L 44 pin PLCC to 44 QFP Cable Converter Development Devices COP8SGR7, COP8SGE7 VL 32k or 8k Eraseable/OTP devices COP8-PM COP8-PM-00 L Included p/s, manuals, software, 16/20/28/40 DIP/SO and 44 PLCC programming socket; add OTP adapter or target adapter (if needed) OTP Programming COP8-PGMA-44QFP Adapters COP8-PGMA-28CSP L For programming 44 QFP on any programmer L For programming 28 CSP on any programmer COP8-PGMA-44CSP L For programming 44 CSP on any programmer COP8-PGMA-28SO VL For programming 16/20/28 SOIC on any programmer DM5-KCOP8-SG M Included p/s (PS-10), target cables (DIP and PLCC), 16/20/28/40 DIP/SO and 44 PLCC programming sockets. Add OTP adapter (if needed) and target adapter (if needed) MHW-CNVxx (xx = 33, 34 etc.) L DM target converters for 16DIP/20SO/28SO/44QFP/28CSP; (i.e. MHW-CNV38 for 20 pin DIP to SO package converter) L For programming 16/20/28 SOIC and 44 PLCC on the EPU MetaLink COP8-DM DM Target Adapters OTP Programming MHW-COP8-PGMA-DS Adapters COP8-IM IM Probe Card IM Probe Target Adapters Order from web site. MHW-COP8-PGMA-44QFP L For programming 44 QFP on any programmer MHW-COP8-PGMA-28CSP L For programming 28 CSP on any programmer IM-COP8-AD-464 (-220) (10 MHz maximum) Base unit 10 MHz; -220 = 220V; add probe card (required) and target adapter (if needed); included software and manuals H PC-COP8SG44PW-AD-10 M 10 MHz 44 PLCC probe card; 2.5V to 6.0V PC-COP8SG40DW-AD-10 M 10 MHz 40 DIP probe card; 2.5V to 6.0V MHW-SOICxx (xx = 16, 20, L 28) 16 or 20 or 28 pin SOIC adapter for probe card MHW-CONV33 L 44 pin QFP adapter for 44 PLCC probe card KKD WCOP8-IDE WCOP8-IDE VL Included in DM and EM IAR EWCOP8-xx See summary above L-H Included all software and manuals Byte Craft COP8C COP8C COP8CWIN M Included all software and manuals Aisys DriveWay COP8 OTP Programmers DriveWay COP8 L Included all software and manuals Go to: www.national.com/cop8 L-H A wide variety world-wide Cost: Free; VL = < $100; L = $100 - $300; M = $300 - $1k; H = $1k - $3k; VH = $3k - $5k www.national.com 56 (Continued) 16.3 WHERE TO GET TOOLS Tools can be ordered directly from National, National's e-store, a National Distributor, or from the tool vendor. Go to the vendor's web site for current listings of distributors. Vendor Home Office Byte Craft Limited Electronic Sites 421 King Street North www.bytecraft.com Waterloo, Ontario info@bytecraft.com Other Main Offices Distributors Worldwide Canada N2J 4E4 Tel: 1-(519) 888-6911 Fax: (519) 746-6751 IAR Systems AB PO Box 23051 www.iar.se USA:: San Francisco S-750 23 Uppsala info@iar.se Tel: +1-415-765-5500 Sweden info@iar.com Fax: +1-415-765-5503 Tel: +46 18 16 78 00 info@iarsys.co.uk UK: London Fax +46 18 16 78 38 info@iar.de Tel: +44 171 924 33 34 Fax: +44 171 924 53 41 Germany: Munich Tel: +49 89 470 6022 Fax: +49 89 470 956 KANDA Systems LTD. Unit 17 -18 Glanyrafon Enterprise Park, Aberystwyth, Ceredigion, SY23 3JQ, UK www.kanda.com support@kanda.com usasupport@kanda.com K and K Development ApS Kaergaardsvej 42 DK-8355 Solbjerg Denmark Fax: +45-8692-8500 www.kkd.dk kkd@kkd.dk National 2900 Semiconductor Dr. www.national.com/cop8 Europe: Santa Clara, CA 95051 support@nsc.com Tel: 49(0) 180 530 8585 USA europe.support@nsc.com Fax: 49(0) 180 530 8586 Semiconductor USA: Tel: 800-331-7766 Fax: 303-456-2404 Tel: 1-800-272-9959 Hong Kong: Fax: 1-800-737-7018 Distributors Worldwide The following companies have approved COP8 programmers in a variety of configurations. Contact your vendor's local office or distributor and request a COP8FLASH update. You can link to their web sites and get the latest listing of approved programmers at: www.national.com/cop8. Advantech; American Reliance; BP Microsystems; Data I/O; Dataman; EE Tools, Hi-Lo Systems; ICE Technology; KANDA, Lloyd Research; Logical Devices; Minato; MQP; Needhams; Phyton; SMS(Data I/O); Stag Programmers; System General; and Tribal Microsystems. 17.0 REVISION HISTORY Date October 2001 Section Summary of Changes Electrical Characteristics Added spec. for comparator enable time. Changed comparator response time to 600 ns. Comparators Added note regarding comparator enable time. 57 www.national.com COP8SG Family 16.0 COP8 Tools Overview COP8SG Family Physical Dimensions inches (millimeters) unless otherwise noted Chip Scale Package CSP Order Number COP8SGR7HLQ8 NS Package Number LQA44A Molded SO Wide Body Package (WM) Order Number COP8SGx528Mx, NS Package Number M28B www.national.com 58 COP8SG Family Physical Dimensions inches (millimeters) unless otherwise noted (Continued) Molded Dual-In-Line Package (N) Order Number COP8SGx728Nx NS Package Number N28B Molded Dual-In-Line Package (N) Order Number COP8SGx540Nx NS Package Number N40A 59 www.national.com COP8SG Family Physical Dimensions inches (millimeters) unless otherwise noted (Continued) 44-Lead EPROM Leaded Chip Carrier (EL) Order Number COP8SGR744J3 NS Package Number EL44C www.national.com 60 COP8SG Family Physical Dimensions inches (millimeters) unless otherwise noted (Continued) Molded Dual-In-Line Package (N) Order Number COP8SGx544Vx NS Package Number V44A 61 www.national.com COP8SG Family, 8-Bit CMOS ROM Based and OTP Microcontrollers with 8k to 32k Memory, Two Comparators and USART Physical Dimensions inches (millimeters) unless otherwise noted (Continued) Plastic Quad Flat Package (VEJ) Order Number COP8SGx544VEJx NS Package Number VEJ44A LIFE SUPPORT POLICY NATIONAL'S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT AND GENERAL COUNSEL OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein: 1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and whose failure to perform when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury to the user. National Semiconductor Corporation Americas Email: support@nsc.com www.national.com National Semiconductor Europe Fax: +49 (0) 180-530 85 86 Email: europe.support@nsc.com Deutsch Tel: +49 (0) 69 9508 6208 English Tel: +44 (0) 870 24 0 2171 Francais Tel: +33 (0) 1 41 91 8790 2. A critical component is any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. National Semiconductor Asia Pacific Customer Response Group Tel: 65-2544466 Fax: 65-2504466 Email: ap.support@nsc.com National Semiconductor Japan Ltd. Tel: 81-3-5639-7560 Fax: 81-3-5639-7507 National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications.