FINAL Am27C256 256 Kilobit (32 K x 8-Bit) CMOS EPROM DISTINCTIVE CHARACTERISTICS Fast access time Latch-up protected to 100 mA from -1 V to VCC + 1 V -- Speed options as fast as 45 ns High noise immunity Low power consumption Versatile features for simple interfacing -- 20 A typical CMOS standby current JEDEC-approved pinout -- Both CMOS and TTL input/output compatibility Single +5 V power supply -- Two line control functions Standard 28-pin DIP, PDIP, and 32-pin PLCC packages 10% power supply tolerance standard 100% FlashriteTM programming -- Typical programming time of 4 seconds GENERAL DESCRIPTION The Am27C256 is a 256-Kbit, ultraviolet erasable programmable read-only memory. It is organized as 32K words by 8 bits per word, operates from a single +5 V supply, has a static standby mode, and features fast single address location programming. Products are available in windowed ceramic DIP packages, as well as plastic one time programmable (OTP) PDIP and PLCC packages. Data can be typically accessed in less than 55 ns, allowing high-performance microprocessors to operate without any WAIT states. The device offers separate Output Enable (OE#) and Chip Enable (CE#) controls, thus eliminating bus contention in a multiple bus microprocessor system. AMD's CMOS process technology provides high speed, low power, and high noise immunity. Typical power consumption is only 80 mW in active mode, and 100 W in standby mode. All signals are TTL levels, including programming signals. Bit locations may be programmed singly, in blocks, or at random. The device supports AMD's Flashrite programming algorithm (100 s pulses), resulting in a typical programming time of 4 seconds. BLOCK DIAGRAM VCC VSS Data Outputs DQ0-DQ7 VPP OE# CE# A0-A14 Address Inputs Output Enable Chip Enable and Prog Logic Output Buffers Y Decoder Y Gating X Decoder 262,144 Bit Cell Matrix 08007I-1 Publication# 08007 Rev: I Issue Date: May 1998 Amendment/0 PRODUCT SELECTOR GUIDE Family Part Number Am27C256 VCC = 5.0 V 5% Speed Options -255 VCC = 5.0 V 10% -45 -55 -70 -90 -120 -150 -200 Max Access Time (ns) 45 55 70 90 120 150 200 250 CE# (E#) Access (ns) 45 55 70 90 120 150 200 250 OE# (G#) Access (ns) 30 35 40 40 50 50 50 50 CONNECTION DIAGRAMS Top View A14 A13 VCC PLCC 28 VCC A12 2 27 A14 4 3 2 1 32 31 30 A7 3 26 A13 A6 5 29 A8 6 28 A9 27 26 A11 NC A6 4 25 A8 A5 A5 5 24 A9 A4 7 8 DU 1 VPP VPP A7 A12 DIP A4 6 23 A11 A3 A3 7 22 OE# (G#) A2 9 25 OE# (G#) A2 8 21 A10 A1 10 24 A10 A0 11 23 CE# (E#) NC 12 22 DQ0 13 21 DQ7 DQ6 A1 9 20 CE# (E#) A0 10 19 DQ7 DQ0 11 18 DQ6 DQ1 12 17 DQ5 DQ2 13 16 DQ4 VSS 14 15 DQ3 DQ5 DQ4 DQ3 VSS DU DQ1 DQ2 14 15 16 17 18 19 20 08007I-3 08007I-2 Notes: 1. JEDEC nomenclature is in parenthesis. 2. Don't use (DU) for PLCC. PIN DESIGNATIONS A0-A14 = Address Inputs CE# (E#) = Chip Enable Input DQ0-DQ7 = Data Input/Outputs OE# (G#) = Output Enable Input VCC = VCC Supply Voltage VPP = Program Voltage Input VSS = Ground NC = No Internal Connection LOGIC SYMBOL 15 8 A0-A14 DQ0-DQ7 CE# (E#) OE# (G#) 08007I-4 2 Am27C256 ORDERING INFORMATION UV EPROM Products AMD standard products are available in several packages and operating ranges. The order number (Valid Combination) is formed by a combination of the following: AM27C256 -45 D C B OPTIONAL PROCESSING Blank = Standard Processing B = Burn-In TEMPERATURE RANGE C = Commercial (0C to +70C) I = Industrial (-40C to +85C) E = Extended (-55C to +125C) PACKAGE TYPE D = 28-Pin Ceramic DIP (CDV028) SPEED OPTION See Product Selector Guide and Valid Combinations DEVICE NUMBER/DESCRIPTION Am27C256 256 Kilobit (32 K x 8-Bit) CMOS UV EPROM Valid Combinations Valid Combinations Valid Combinations list configurations planned to be supported in volume for this device. Consult the local AMD sales office to confirm availability of specific valid combinations and to check on newly released combinations. AM27C256-45 DC, DCB, DI, DIB AM27C256-55 AM27C256-70 AM27C256-90 AM27C256-120 DC, DCB, DI, DIB, DE, DEB AM27C256-150 AM27C256-200 AM27C256-255 VCC = 5.0 V 5% DC, DCB, DI, DIB Am27C256 3 ORDERING INFORMATION OTP EPROM Products AMD standard products are available in several packages and operating ranges. The order number (Valid Combination) is formed by a combination of the following: AM27C256 -55 P C OPTIONAL PROCESSING Blank = Standard Processing TEMPERATURE RANGE C = Commercial (0C to +70C) I = Industrial (-40C to +85C) PACKAGE TYPE P = 28-Pin Plastic DIP (PD 028) J = 32-Pin Square Plastic Leaded Chip Carrier (PL 032) SPEED OPTION See Product Selector Guide and Valid Combinations DEVICE NUMBER/DESCRIPTION Am27C256 256 Kilobit (32 K x 8-Bit) CMOS OTP EPROM Valid Combinations Valid Combinations AM27C256-55 JC, PC AM27C256-70 Valid Combinations list configurations planned to be supported in volume for this device. Consult the local AMD sales office to confirm availability of specific valid combinations and to check on newly released combinations. AM27C256-90 AM27C256-120 JC, PC, JI, PI AM27C256-150 AM27C256-200 AM27C256-255 4 Am27C256 FUNCTIONAL DESCRIPTION Device Erasure In order to clear all locations of their programmed contents, the device must be exposed to an ultraviolet light source. A dosage of 15 W seconds/cm2 is required to completely erase the device. This dosage can be obtained by exposure to an ultraviolet lamp--wavelength of 2537 A--with intensity of 12,000 W/cm2 for 15 to 20 minutes. The device should be directly under and about one inch from the source, and all filters should be removed from the UV light source prior to erasure. Note that all UV erasable devices will erase with light sources having wavelengths shorter than 4000 A, such as fluorescent light and sunlight. Although the erasure process happens over a much longer time period, exposure to any light source should be prevented for maximum system reliability. Simply cover the package window with an opaque label or substance. Device Programming Upon delivery, or after each erasure, the device has all of its bits in the "ONE", or HIGH state. "ZEROs" are loaded into the device through the programming procedure. The device enters the programming mode when 12.75 V 0.25 V is applied to the VPP pin, OE# is at VIH and CE# is at VIL. For programming, the data to be programmed is applied 8 bits in parallel to the data pins. The flowchar t in the Programming section of the EPROM Products Data Book (Section 5, Figure 5-1) shows AMD's Flashrite algorithm. The Flashrite algorithm reduces programming time by using a 100 s programming pulse and by giving each address only as many pulses to reliably program the data. After each pulse is applied to a given address, the data in that address is verified. If the data does not verify, additional pulses are given until it verifies or the maximum pulses allowed is reached. This process is repeated while sequencing through each address of the device. This part of the algorithm is done at VCC = 6.25 V to assure that each EPROM bit is programmed to a sufficiently high threshold voltage. After the final address is completed, the entire EPROM memory is verified at VCC = VPP = 5.25 V. Please refer to Section 5 of the EPROM Products Data Book for additional programming information and specifications. Program Inhibit Programming different data to multiple devices in parallel is easily accomplished. Except for CE#, all like inputs of the devices may be common. A TTL low-level program pulse applied to one device's CE# input with VPP = 12.75 V 0.25 V and OE# HIGH will program that particular device. A high-level CE# input inhibits the other devices from being programmed. Program Verify A verification should be performed on the programmed bits to determine that they were correctly programmed. The verify should be performed with OE# at VIL, CE# at VIH, and VPP between 12.5 V and 13.0 V. Autoselect Mode The autoselect mode provides manufacturer and device identification through identifier codes on DQ0- DQ7. This mode is primarily intended for programming equipment to automatically match a device to be programmed with its corresponding programming algorithm. This mode is functional in the 25C 5C ambient temperature range that is required when programming the device. To activate this mode, the programming equipment must force VH on address line A9. Two identifier bytes may then be sequenced from the device outputs by toggling address line A0 from VIL to VIH (that is, changing the address from 00h to 01h). All other address lines must be held at VIL during the autoselect mode. Byte 0 (A0 = VIL) represents the manufacturer code, and Byte 1 (A0 = VIH), the device identifier code. Both codes have odd parity, with DQ7 as the parity bit. Read Mode To obtain data at the device outputs, Chip Enable (CE#) and Output Enable (OE#) must be driven low. CE# controls the power to the device and is typically used to select the device. OE# enables the device to output data, independent of device selection. Addresses must be stable for at least tACC -tOE. Refer to the Switching Waveforms section for the timing diagram. Standby Mode The device enters the CMOS standby mode when CE# is at VCC 0.3 V. Maximum VCC current is reduced to 100 A. The device enters the TTL-standby mode when CE# is at VIH. Maximum VCC current is reduced to 1.0 mA. When in either standby mode, the device places its outputs in a high-impedance state, independent of the OE# input. Output OR-Tieing To accommodate multiple memory connections, a two-line control function provides: Low memory power dissipation, and Assurance that output bus contention will not occur. CE# should be decoded and used as the primary device-selecting function, while OE# be made a common Am27C256 5 connection to all devices in the array and connected to the READ line from the system control bus. This assures that all deselected memory devices are in their low-power standby mode and that the output pins are only active when data is desired from a particular memory device. these transient current peaks is dependent on the output capacitance loading of the device. At a minimum, a 0.1 F ceramic capacitor (high frequency, low inherent inductance) should be used on each device between VCC and VSS to minimize transient effects. In addition, to overcome the voltage drop caused by the inductive effects of the printed circuit board traces on EPROM arrays, a 4.7 F bulk electrolytic capacitor should be used between VCC and VSS for each eight devices. The location of the capacitor should be close to where the power supply is connected to the array. System Applications During the switch between active and standby conditions, transient current peaks are produced on the rising and falling edges of Chip Enable. The magnitude of MODE SELECT TABLE Mode CE# OE# A0 A9 VPP Outputs Read VIL VIL X X X DOUT Output Disable X VIH X X X High Z Standby (TTL) VIH X X X X High Z VCC 0.3 V X X X X High Z Program VIL X X X VPP DIN Program Verify VIL VIL X X VPP DOUT Program Inhibit VIH VIH X X VPP High Z Manufacturer Code VIL VIL VIL VH X 01h Device Code VIL VIL VIH VH X 10h Standby (CMOS) Autoselect (Note 3) Notes: 1. VH = 12.0 V 0.5 V. 2. X = Either VIH or VIL. 3. A1-A8 and A10-14 = VIL 4. See DC Programming Characteristics for VPP voltage during programming. 6 Am27C256 ABSOLUTE MAXIMUM RATINGS OPERATING RANGES Storage Temperature OTP Products. . . . . . . . . . . . . . . . . . -65C to +125C All Other Products . . . . . . . . . . . . . . -65C to +150C Commercial (C) Devices Ambient Temperature with Power Applied. . . . . . . . . . . . . . -55C to +125C Ambient Temperature (TA) . . . . . . . . . . .0C to +70C Industrial (I) Devices Ambient Temperature (TA) . . . . . . . . .-40C to +85C Voltage with Respect to VSS All pins except A9, VPP, VCC . . -0.6 V to VCC + 0.6 V Extended (E) Devices A9 and VPP (Note 2) . . . . . . . . . . . . . -0.6 V to 13.5 V Supply Read Voltages VCC (Note 1). . . . . . . . . . . . . . . . . . . . . -0.6 V to 7.0 V VCC for 5% devices . . . . . . . . . . +4.75 V to +5.25 V VCC for 10% devices . . . . . . . . . +4.50 V to +5.50 V Notes: 1. Minimum DC voltage on input or I/O pins -0.5 V. During voltage transitions, the input may overshoot VSS to -2.0 V for periods of up to 20 ns. Maximum DC voltage on input and I/O pins is VCC + 5 V. During voltage transitions, input and I/O pins may overshoot to VCC + 2.0 V for periods up to 20 ns. Ambient Temperature (TA) . . . . . . . .-55C to +125C Operating ranges define those limits between which the functionality of the device is guaranteed. 2. Minimum DC input voltage on A9 is -0.5 V. During voltage transitions, A9 and VPP may overshoot VSS to -2.0 V for periods of up to 20 ns. A9 and VPP must not exceed +13.5 V at any time. Stresses above those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. This is a stress rating only; functional operation of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied. Exposure of the device to absolute maximum ratings for extended periods may affect device reliability. Am27C256 7 DC CHARACTERISTICS over operating range (unless otherwise specified) Parameter Symbol Parameter Description Test Conditions Min Max 2.4 Unit VOH Output HIGH Voltage IOH = -400 A V VOL Output LOW Voltage IOL = 2.1 mA VIH Input HIGH Voltage VIL Input LOW Voltage ILI Input Load Current VIN = 0 V to VCC ILO Output Leakage Current VOUT = 0 V to VCC ICC1 VCC Active Current (Note 2) CE# = VIL, f = 10 MHz, IOUT = 0 mA 25 mA ICC2 VCC TTL Standby Current CE# = VIH 1.0 mA ICC3 VCC CMOS Standby Current CE# = VCC 0.3 V 100 A IPP1 VPP Supply Current (Read) CE# = OE# = VIL, VPP = VCC 100 A 0.45 V 2.0 VCC + 0.5 V -0.5 +0.8 V 1.0 A C/I Devices 1.0 E Devices 5.0 A Caution: The device must not be removed from (or inserted into) a socket when VCC or VPP is applied. Notes: 1. VCC must be applied simultaneously or before VPP, and removed simultaneously or after VPP.. 2. ICC1 is tested with OE# = VIH to simulate open outputs. 30 30 25 25 Supply Current in mA Supply Current in mA 3. Minimum DC Input Voltage is -0.5 V. During transitions, the inputs may overshoot to -2.0 V for periods less than 20 ns. Maximum DC Voltage on output pins is VCC + 0.5 V, which may overshoot to VCC + 2.0 V for periods less than 20 ns. 20 15 Figure 1. 8 2 3 4 5 6 7 Frequency in MHz 8 9 15 10 -75 -50 -55 10 1 20 10 0 25 50 75 100 125 150 Temperature in C 08007I-5 08007I-6 Typical Supply Current vs. Frequency VCC = 5.5 V, T = 25C Figure 2. Typical Supply Current vs. Temperature VCC = 5.5 V, f = 10 MHz Am27C256 TEST CONDITIONS Table 1. 5.0 V -45, -55 and -70 Test Condition 2.7 k Device Under Test Test Specifications Output Load CL 30 Input Pulse Levels 08007I-7 Figure 3. 100 pF 20 Input Rise and Fall Times Note: Diodes are IN3064 or equivalents. Unit 1 TTL gate Output Load Capacitance, CL (including jig capacitance) 6.2 k All others ns 0.0-3.0 0.45-2.4 V Input timing measurement reference levels 1.5 0.8, 2.0 V Output timing measurement reference levels 1.5 0.8, 2.0 V Test Setup SWITCHING TEST WAVEFORM 3V 2.4 V 2.0 V 2.0 V Test Points 1.5 V Test Points 1.5 V 0.8 V 0V 0.8 V 0.45 V Input Output Output Input Note: For CL = 30 pF. Note: For CL = 100 pF. 08007I-8 KEY TO SWITCHING WAVEFORMS WAVEFORM INPUTS OUTPUTS Steady Changing from H to L Changing from L to H Don't Care, Any Change Permitted Changing, State Unknown Does Not Apply Center Line is High Impedance State (High Z) KS000010-PAL Am27C256 9 AC CHARACTERISTICS Parameter Symbols JEDEC Standard tAVQV tACC tELQV Am27C256 Description Test Setup -45 -55 -70 -90 -120 -150 -200 -255 Unit Address to Output Delay CE#, Max OE# = VIL 45 55 70 90 120 150 200 250 ns tCE Chip Enable to Output Delay OE# = VIL Max 45 55 70 90 120 150 200 250 ns tGLQV tOE Output Enable to Output Delay CE# = VIL Max 30 35 40 40 50 50 50 50 ns tEHQZ tGHQZ tDF (Note 2) Chip Enable High or Output Enable High to Output High Z, Whichever Occurs First Max 25 25 25 25 30 30 30 30 ns tAXQX tOH Output Hold Time from Addresses, CE# or OE#, Whichever Occurs First Min 0 0 0 0 0 0 0 0 ns Caution: Do not remove the device from (or insert it into) a socket or board that has VPP or VCC applied. Notes: 1. VCC must be applied simultaneously or before VPP, and removed simultaneously or after VPP. 2. This parameter is sampled and not 100% tested. 3. Switching characteristics are over operating range, unless otherwise specified. 4. See Figure 3 and Table 1 for test specifications. SWITCHING WAVEFORMS 2.4 Addresses 0.45 2.0 0.8 2.0 0.8 Addresses Valid CE# tCE OE# tDF (Note 2) tOE Output High Z tACC (Note 1) tOH High Z Valid Output 08007I-9 Notes: 1. OE# may be delayed up to tACC - tOE after the falling edge of the addresses without impact on tACC. 2. tDF is specified from OE# or `CE#, whichever occurs first. PACKAGE CAPACITANCE Parameter Symbol CIN COUT Parameter Description CDV028 Test Conditions PD 028 Typ Max Typ Max Typ Max Unit Input Capacitance VIN = 0 8 12 8 12 6 10 pF Output Capacitance VOUT = 0 8 12 8 12 8 10 pF Notes: 1. This parameter is only sampled and not 100% tested. 2. TA = +25C, f = 1 MHz. 10 PL 032 Am27C256 PHYSICAL DIMENSIONS* CDV028--28-Pin Ceramic Dual In-Line Package, UV Lens (measured in inches) DATUM D CENTER PLANE UV Lens .565 .605 INDEX AND TERMINAL NO. 1 I.D. AREA 1 TOP VIEW DATUM D CENTER PLANE 1.435 1.490 .160 .220 BASE PLANE SEATING PLANE .015 .060 .700 MAX 94 105 .125 .200 .300 BSC .005 MIN .600 BSC .045 .065 .008 .018 .100 BSC .014 .026 END VIEW SIDE VIEW 16-000038H-3 CDV028 DF10 3-30-95 ae * For reference only. BSC is an ANSI standard for Basic Space Centering. PD 028--28-Pin Plastic Dual In-Line Package (measured in inches) 1.440 1.480 .600 .625 15 28 .530 .580 Pin 1 I.D. .008 .015 .630 .700 14 .045 .065 0 10 .005 MIN .140 .225 SEATING PLANE .120 .160 .090 .110 .014 .022 .015 .060 Am27C256 16-038-SB-AG PD 028 DG75 7-13-95 ae 11 PHYSICAL DIMENSIONS PL 032--32-Pin Plastic Leaded Chip Carrier (measured in inches) .447 .453 .485 .495 .009 .015 .585 .595 .042 .056 .125 .140 Pin 1 I.D. .080 .095 .547 .553 SEATING PLANE .400 REF. .490 .530 .013 .021 .050 REF. .026 .032 TOP VIEW SIDE VIEW 16-038FPO-5 PL 032 DA79 6-28-94 ae l REVISION SUMMARY FOR AM27C256 Revision I Ordering Information UV EPROM Products: Added the AM27C256-45 Valid Combination. Global Changed formatting to match current data sheets. Test Conditions Distinctive Characteristics Fast access time: Changed "Speed options as fast as 55 ns" to "Speed options as fast as 45 ns". Table 1. Test Specifications: Added the -45 speed option. AC Characteristics Product Selector Guide Added the -45 speed option. Added the -45 speed option. Trademarks Copyright (c) 1998 Advanced Micro Devices, Inc. All rights reserved. AMD, the AMD logo, and combinations thereof are trademarks of Advanced Micro Devices, Inc. Flashrite is a trademark of Advanced Micro Devices, Inc. Product names used in this publication are for identification purposes only and may be trademarks of their respective companies. 12 Am27C256