1. General description
The SC16IS740/750/760 is a slave I2C-bus/SPI interface to a single-channel high
performance UART. It offers data rates up to 5 Mbit/s and guarantees low operating and
sleeping current. The SC16IS750 and SC16IS760 also provide the application with 8
additional programmable I/O pins. The device comes in very small HVQFN24, TSSOP24
(SC16IS750/760) and TSSOP16 (SC16IS740) packages, which makes it ideally suitable
for handheld, battery operated applications. This family of products enables seamless
protocol conversion from I2C-bus or SPI to and RS-232/RS-485 and are fully bidirectional.
The SC16IS760 differs from the SC16IS750 in that it supports SPI clock speeds up to
15 Mbit/s instead of the 4 Mbit/s supported by the SC16IS750, and in that it supports
IrDA SIR up to 1.152 Mbit/s. In all other aspects, the SC16IS760 is functionally and
electrically the same as the SC16IS750. The SC16IS740 is functionally and electrically
identical to the SC16IS750, with the exception of the programmable I/O pins which are
only present on the SC16IS750.
The SC16IS740/750/760’s internal register set is backward-compatible with the widely
used and widely popular 16C450. This allows the software to be easily written or ported
from another platform.
The SC16IS740/750/760 also provides additional advanced features such as auto
hardware and software flow control, automatic RS-485 support, and software reset. This
allows the software to reset the UART at any moment, independent of the hardware reset
signal.
2. Features
2.1 General features
nSingle full-duplex UART
nSelectable I2C-bus or SPI interface
n3.3 V or 2.5 V operation
nIndustrial temperature range: 40 °C to +95 °C
n64 bytes FIFO (transmitter and receiver)
nFully compatible with industrial standard 16C450 and equivalent
nBaud rates up to 5 Mbit/s in 16× clock mode
nAuto hardware flow control using RTS/CTS
nAuto software flow control with programmable Xon/Xoff characters
nSingle or double Xon/Xoff characters
nAutomatic RS-485 support (automatic slave address detection)
SC16IS740/750/760
Single UART with I2C-bus/SPI interface, 64 bytes of transmit
and receive FIFOs, IrDA SIR built-in support
Rev. 06 — 13 May 2008 Product data sheet
SC16IS740_750_760_6 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 06 — 13 May 2008 2 of 62
NXP Semiconductors SC16IS740/750/760
Single UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
nUp to eight programmable I/O pins (SC16IS750 and SC16IS760 only)
nRS-485 driver direction control via RTS signal
nRS-485 driver direction control inversion
nBuilt-in IrDA encoder and decoder interface
nSC16IS750 supports IrDA SIR with speeds up to 115.2 kbit/s
nSC16IS760 supports IrDA SIR with speeds up to 1.152 Mbit/s1
nSoftware reset
nTransmitter and receiver can be enabled/disabled independent of each other
nReceive and Transmit FIFO levels
nProgrammable special character detection
nFully programmable character formatting
u5-bit, 6-bit, 7-bit or 8-bit character
uEven, odd, or no parity
u1, 112, or 2 stop bits
nLine break generation and detection
nInternal Loopback mode
nSleep current less than 30 µA at 3.3 V
nIndustrial and commercial temperature ranges
nAvailable in HVQFN24, TSSOP24 (SC16IS750/760) and TSSOP16 (SC16IS740)
packages
2.2 I2C-bus features
nNoise filter on SCL/SDA inputs
n400 kbit/s maximum speed
nCompliant with I2C-bus fast speed
nSlave mode only
2.3 SPI features
nSC16IS750 supports 4 Mbit/s maximum SPI clock speed
nSC16IS760 supports 15 Mbit/s maximum SPI clock speed
nSlave mode only
nSPI Mode 0
3. Applications
nFactory automation and process control
nPortable and battery operated devices
nCellular data devices
1. Please note that IrDA SIR at 1.152 Mbit/s is not compatible with IrDA MIR at that speed. Please refer to application notes for usage
of IrDA SIR at 1.152 Mbit/s.
SC16IS740_750_760_6 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 06 — 13 May 2008 3 of 62
NXP Semiconductors SC16IS740/750/760
Single UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
4. Ordering information
Table 1. Ordering information
Type number Package
Name Description Version
SC16IS740IPW TSSOP16 plastic thin shrink small outline package; 16 leads; body width 4.4 mm SOT403-1
SC16IS750IBS HVQFN24 plastic thermal enhanced very thin quad flat package; no leads;
24 terminals; body 4 ×4×0.85 mm SOT616-3
SC16IS750IPW TSSOP24 plastic thin shrink small outline package; 24 leads; body width 4.4 mm SOT355-1
SC16IS760IBS HVQFN24 plastic thermal enhanced very thin quad flat package; no leads;
24 terminals; body 4 ×4×0.85 mm SOT616-3
SC16IS760IPW TSSOP24 plastic thin shrink small outline package; 24 leads; body width 4.4 mm SOT355-1
SC16IS740_750_760_6 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 06 — 13 May 2008 4 of 62
NXP Semiconductors SC16IS740/750/760
Single UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
5. Block diagram
Fig 1. Block diagram of SC16IS750/760 I2C-bus interface
Fig 2. Block diagram of SC16IS740 I2C-bus interface
SC16IS750/760
16C450
COMPATIBLE
REGISTER
SETS
002aab014
VDD
I2C-BUS
TX
RX
RTS
GPIO
REGISTER
CTS
GPIO[3:0]
XTAL1 XTAL2
SCL
SDA
A0
IRQ
I2C/SPI
4
A1
RESET
GPIO4/DSR
GPIO5/DTR
GPIO6/CD
GPIO7/RI
VDD
VSS
VDD
1 k (3.3 V)
1.5 k (2.5 V)
SC16IS740
16C450
COMPATIBLE
REGISTER
SETS
002aab971
VDD
I2C-BUS
TX
RX
RTS
CTS
XTAL1 XTAL2
SCL
SDA
A0
IRQ
I2C/SPI
A1
RESET
VDD
VSS
VDD
1 k (3.3 V)
1.5 k (2.5 V)
SC16IS740_750_760_6 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 06 — 13 May 2008 5 of 62
NXP Semiconductors SC16IS740/750/760
Single UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
Fig 3. Block diagram of SC16IS750/760 SPI interface
Fig 4. Block diagram of SC16IS740 SPI interface
CS
SC16IS750/760
16C450
COMPATIBLE
REGISTER
SETS
002aab396
SPI
TX
RX
RTS
GPIO
REGISTER
CTS
GPIO[3:0]
XTAL1 XTAL2
SCLK
SO
IRQ
I2C/SPI
4
SI
RESET
GPIO4/DSR
GPIO5/DTR
GPIO6/CD
GPIO7/RI
VDD
VSS
VDD
1 k (3.3 V)
1.5 k (2.5 V)
CS
SC16IS740
16C450
COMPATIBLE
REGISTER
SETS
002aab972
SPI
TX
RX
RTS
CTS
XTAL1 XTAL2
SCLK
SO
IRQ
I2C/SPI
SI
RESET
VDD
VSS
VDD
1 k (3.3 V)
1.5 k (2.5 V)
SC16IS740_750_760_6 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 06 — 13 May 2008 6 of 62
NXP Semiconductors SC16IS740/750/760
Single UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
6. Pinning information
6.1 Pinning
a. I2C-bus interface b. SPI interface
Fig 5. Pin configuration for TSSOP16
SC16IS740IPW
VDD XTAL2
A0 XTAL1
A1 RESET
n.c. RX
SCL TX
SDA CTS
IRQ RTS
I2C VSS
002aab973
1
2
3
4
5
6
7
8
10
9
12
11
14
13
16
15
SC16IS740IPW
VDD XTAL2
CS XTAL1
SI RESET
SO RX
SCLK TX
VSS CTS
IRQ RTS
SPI VSS
002aab974
1
2
3
4
5
6
7
8
10
9
12
11
14
13
16
15
a. I2C-bus interface b. SPI interface
Fig 6. Pin configuration for TSSOP24
XTAL2
XTAL1
RESET
RX
TX
CTS RTS
GPIO7/RI
GPIO6/CD
GPIO5/DTR
GPIO4/DSR
VSS
VDD
A0
A1
n.c.
SDA
IRQ
GPIO0
GPIO1
GPIO2
SCL
I2C
SC16IS750IPW
SC16IS760IPW GPIO3
002aab016
1
2
3
4
5
6
7
8
9
10
11
12
14
13
16
15
18
17
20
19
22
21
24
23
XTAL2
XTAL1
RESET
RX
TX
CTS RTS
GPIO7/RI
GPIO6/CD
GPIO5/DTR
GPIO4/DSR
VSS
VDD
CS
SI
SO
VSS
IRQ
GPIO0
GPIO1
GPIO2
GPIO3
SCLK
SPI
SC16IS750IPW
SC16IS760IPW
002aab399
1
2
3
4
5
6
7
8
9
10
11
12
14
13
16
15
18
17
20
19
22
21
24
23
SC16IS740_750_760_6 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 06 — 13 May 2008 7 of 62
NXP Semiconductors SC16IS740/750/760
Single UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
6.2 Pin description
a. I2C-bus interface b. SPI interface
Fig 7. Pin configuration for HVQFN24
RTS
GPIO7/RI
GPIO6/CD
RX
TX
CTS
A0
I2C
VDD
XTAL1
RESET
XTAL2
n.c.
A1
IRQ
SDA
SCL
GPIO0
002aab015
GPIO5/DTR
GPIO4/DSR
GPIO3
GPIO2
GPIO1
VSS
SC16IS750IBS
SC16IS760IBS
Transparent top view
terminal 1
index area
613
514
4 15
3 16
2 17
118
7
8
9
10
11
12
24
23
22
21
20
19
RTS
GPIO7/RI
GPIO6/CD
RX
TX
CTS
CS
SPI
VDD
XTAL1
RESET
XTAL2
SO
SI
IRQ
VSS
SCLK
GPIO0
002aab401
GPIO5/DTR
GPIO4/DSR
GPIO3
GPIO2
GPIO1
VSS
SC16IS750IBS
SC16IS760IBS
Transparent top view
terminal 1
index area
613
514
4 15
3 16
2 17
118
7
8
9
10
11
12
24
23
22
21
20
19
Table 2. Pin description
Symbol Pin Type Description
TSSOP16 TSSOP24 HVQFN24
CTS 11 1 22 I UART clear to send (active LOW). A logic 0 (LOW) on the CTS
pin indicates the modem or data set is ready to accept transmit
data from the SC16IS740/750/760. Status can be tested by
reading MSR[4]. This pin only affects the transmit and receive
operations when auto CTS function is enabled via the Enhanced
Feature Register EFR[7] for hardware flow control operation.
TX 12 2 23 O UART transmitter output. During the local Loopback mode, the
TX output pin is disabled and TX data is internally connected to
the UART RX input.
RX 13 3 24 I UART receiver input. During the local Loopback mode, the RX
input pin is disabled and TX data is connected to the UART RX
input internally.
RESET 14 4 1 I device hardware reset (active LOW)[1]
XTAL1 15 5 2 I Crystal input or external clock input. Functions as a crystal input
or as an external clock input. A crystal can be connected
between XTAL1 and XTAL2 to form an internal oscillator circuit
(see Figure 15). Alternatively, an external clock can be
connected to this pin.
XTAL2 16 6 3 O Crystal output or clock output. (See also XTAL1.) XTAL2 is used
as a crystal oscillator output.
VDD 1 7 4 - power supply
I2C/SPI 8 8 5 I I2C-bus or SPI interface select. I2C-bus interface is selected if
this pin is at logic HIGH. SPI interface is selected if this pin is at
logic LOW.
SC16IS740_750_760_6 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 06 — 13 May 2008 8 of 62
NXP Semiconductors SC16IS740/750/760
Single UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
[1] See Section 7.4 “Hardware reset, Power-On Reset (POR) and software reset”
[2] Selectable with IOControl register bit 1.
CS/A0 2 9 6 I SPI chip select or I2C-bus device address select A0. If SPI
configuration is selected by I2C/SPI pin, this pin is the SPI chip
select pin (Schmitt-trigger, active LOW). If I2C-bus configuration
is selected by I2C/SPI pin, this pin along with A1 pin allows user
to change the device’s base address.
SI/A1 3 10 7 I SPI data input pin or I2C-bus device address select A1. If SPI
configuration is selected by I2C/SPI pin, this is the SPI data
input pin. If I2C-bus configuration is selected by I2C/SPI pin, this
pin along with A0 pin allows user to change the device’s base
address. To select the device address, please refer to Table 32.
SO 4 11 8 O SPI data output pin. If SPI configuration is selected by I2C/SPI
pin, this is a 3-stateable output pin. If I2C-bus configuration is
selected by I2C/SPI pin, this pin function is undefined and must
be left as n.c. (not connected).
SCL/SCLK 5 12 9 I I2C-bus or SPI input clock.
SDA 6 13 10 I/O I2C-bus data input/output, open-drain if I2C-bus configuration is
selected by I2C/SPI pin. If SPI configuration is selected then this
pin is an undefined pin and must be connected to VSS.
IRQ 7 14 11 O Interrupt (open-drain, active LOW). Interrupt is enabled when
interrupt sources are enabled in the Interrupt Enable Register
(IER). Interrupt conditions include: change of state of the input
pins, receiver errors, available receiver buffer data, available
transmit buffer space, or when a modem status flag is detected.
An external resistor (1 k for 3.3 V, 1.5 kfor 2.5 V) must be
connected between this pin and VDD.
GPIO0 - 15 12 I/O programmable I/O pin
GPIO1 - 16 13 I/O programmable I/O pin
GPIO2 - 17 14 I/O programmable I/O pin
GPIO3 - 18 15 I/O programmable I/O pin
GPIO4/DSR - 20 17 I/O programmable I/O pin or modem’s DSR pin[2]
GPIO5/DTR - 21 18 I/O programmable I/O pin or modem’s DTR pin[2]
GPIO6/CD - 22 19 I/O programmable I/O pin or modem’s CD pin[2]
GPIO7/RI - 23 20 I/O programmable I/O pin or modem’s RI pin[2]
RTS 10 24 21 O UART request to send (active LOW). A logic 0 on the RTS pin
indicates the transmitter has data ready and waiting to send.
Writing a logic 1 in the modem control register MCR[1] will set
this pin to a logic 0, indicating data is available. After a reset this
pin is set to a logic 1. This pin only affects the transmit and
receive operations when auto RTS function is enabled via the
Enhanced Feature Register (EFR[6]) for hardware flow control
operation.
VSS 91916
[3] - ground
VSS - - center
pad[3] - The center pad on the back side of the HVQFN24 package is
metallic and should be connected to ground on the
printed-circuit board.
Table 2. Pin description
…continued
Symbol Pin Type Description
TSSOP16 TSSOP24 HVQFN24
SC16IS740_750_760_6 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 06 — 13 May 2008 9 of 62
NXP Semiconductors SC16IS740/750/760
Single UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
[3] HVQFN24 package die supply ground is connected to both VSS pins and exposed center pad. VSS pins must be connected to supply
ground for proper device operation. For enhanced thermal, electrical, and board level performance, the exposed pad needs to be
soldered to the board using a corresponding thermal pad on the board and for proper heat conduction through the board, thermal vias
need to be incorporated in the PCB in the thermal pad region.
7. Functional description
The UART will perform serial-to-I2C conversion on data characters received from
peripheral devices or modems, and I2C-to-serial conversion on data characters
transmitted by the host. The complete status the SC16IS740/750/760 UART can be read
at any time during functional operation by the host.
The SC16IS740/750/760 can be placed in an alternate mode (FIFO mode) relieving the
host of excessive software overhead by buffering received/transmitted characters. Both
the receiver and transmitter FIFOs can store up to 64 characters (including three
additional bits of error status per character for the receiver FIFO) and have selectable or
programmable trigger levels.
The SC16IS740/750/760 has selectable hardware flow control and software flow control.
Hardware flow control significantly reduces software overhead and increases system
efficiency by automatically controlling serial data flow using the RTS output and CTS input
signals. Software flow control automatically controls data flow by using programmable
Xon/Xoff characters.
The UART includes a programmable baud rate generator that can divide the timing
reference clock input by a divisor between 1 and (216 1).
7.1 Trigger levels
The SC16IS740/750/760 provides independently selectable and programmable trigger
levels for both receiver and transmitter interrupt generation. After reset, both transmitter
and receiver FIFOs are disabled and so, in effect, the trigger level is the default value of
one character. The selectable trigger levels are available via the FCR. The programmable
trigger levels are available via the TLR. If TLR bits are cleared then selectable trigger level
in FCR is used. If TLR bits are not cleared then programmable trigger level in TLR is used.
7.2 Hardware flow control
Hardware flow control is comprised of auto CTS and auto RTS (see Figure 8). Auto CTS
and auto RTS can be enabled/disabled independently by programming EFR[7:6].
With auto CTS, CTS must be active before the UART can transmit data.
Auto RTS only activates the RTS output when there is enough room in the FIFO to receive
data and de-activates the RTS output when the RX FIFO is sufficiently full. The halt and
resume trigger levels in the TCR determine the levels at which RTS is
activated/deactivated. If TCR bits are cleared then selectable trigger levels in FCR are
used in place of TCR.
If both auto CTS and auto RTS are enabled, when RTS is connected to CTS, data
transmission does not occur unless the receiver FIFO has empty space. Thus, overrun
errors are eliminated during hardware flow control. If not enabled, overrun errors occur if
the transmit data rate exceeds the receive FIFO servicing latency.
SC16IS740_750_760_6 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 06 — 13 May 2008 10 of 62
NXP Semiconductors SC16IS740/750/760
Single UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
7.2.1 Auto RTS
Figure 9 shows RTS functional timing. The receiver FIFO trigger levels used in auto RTS
are stored in the TCR or FCR. RTS is active if the RX FIFO level is below the halt trigger
level in TCR[3:0]. When the receiver FIFO halt trigger level is reached, RTS is deasserted.
The sending device (for example, another UART) may send an additional character after
the trigger level is reached (assuming the sending UART has another character to send)
because it may not recognize the deassertion of RTS until it has begun sending the
additional character. RTS is automatically reasserted once the receiver FIFO reaches the
resume trigger level programmed via TCR[7:4]. This reassertion allows the sending
device to resume transmission.
Fig 8. Autoflow control (auto RTS and auto CTS) example
RX
FIFO
FLOW
CONTROL
TX
FIFO
PARALLEL
TO SERIAL
TX
FIFO
RX
FIFO
UART 1 UART 2
RX TX
RTS CTS
TX RX
CTS RTS
002aab656
SERIAL TO
PARALLEL
SERIAL TO
PARALLEL
FLOW
CONTROL
FLOW
CONTROL
FLOW
CONTROL
PARALLEL
TO SERIAL
(1) N = receiver FIFO trigger level.
(2) The two blocks in dashed lines cover the case where an additional character is sent, as described in Section 7.2.1
Fig 9. RTS functional timing
start character
Nstart character
N + 1 startstop stopRX
RTS
receive
FIFO
read
N N + 112
002aab040
SC16IS740_750_760_6 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 06 — 13 May 2008 11 of 62
NXP Semiconductors SC16IS740/750/760
Single UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
7.2.2 Auto CTS
Figure 10 shows CTS functional timing. The transmitter circuitry checks CTS before
sending the next data byte. When CTS is active, the transmitter sends the next byte. To
stop the transmitter from sending the following byte, CTS must be deasserted before the
middle of the last stop bit that is currently being sent. The auto CTS function reduces
interrupts to the host system. When flow control is enabled, CTS level changes do not
trigger host interrupts because the device automatically controls its own transmitter.
Without auto CTS, the transmitter sends any data present in the transmit FIFO and a
receiver overrun error may result.
7.3 Software flow control
Software flow control is enabled through the enhanced feature register and the Modem
Control Register. Different combinations of software flow control can be enabled by setting
different combinations of EFR[3:0]. Table 3 shows software flow control options.
(1) When CTS is LOW, the transmitter keeps sending serial data out.
(2) When CTS goes HIGH before the middle of the last stop bit of the current character, the transmitter finishes sending the current
character, but it does not send the next character.
(3) When CTS goes from HIGH to LOW, the transmitter begins sending data again.
Fig 10. CTS functional timing
start bit 0 to bit 7 stopTX
CTS
002aab041
start stop
bit 0 to bit 7
Table 3. Software flow control options (EFR[3:0])
EFR[3] EFR[2] EFR[1] EFR[0] TX, RX software flow control
0 0 X X no transmit flow control
1 0 X X transmit Xon1, Xoff1
0 1 X X transmit Xon2, Xoff2
1 1 X X transmit Xon1 and Xon2, Xoff1 and Xoff2
X X 0 0 no receive flow control
X X 1 0 receiver compares Xon1, Xoff1
X X 0 1 receiver compares Xon2, Xoff2
1011transmit Xon1, Xoff1
receiver compares Xon1 or Xon2, Xoff1 or Xoff2
0111transmit Xon2, Xoff2
receiver compares Xon1 or Xon2, Xoff1 or Xoff2
1111transmit Xon1 and Xon2, Xoff1 and Xoff2
receiver compares Xon1 and Xon2, Xoff1 and Xoff2
0011no transmit flow control
receiver compares Xon1 and Xon2, Xoff1 and Xoff2
SC16IS740_750_760_6 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 06 — 13 May 2008 12 of 62
NXP Semiconductors SC16IS740/750/760
Single UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
There are two other enhanced features relating to software flow control:
Xon Any function (MCR[5]): Receiving any character will resume operation after
recognizing the Xoff character. It is possible that an Xon1 character is recognized as
an Xon Any character, which could cause an Xon2 character to be written to the RX
FIFO.
Special character (EFR[5]): Incoming data is compared to Xoff2. Detection of the
special character sets the Xoff interrupt (IIR[4]) but does not halt transmission. The
Xoff interrupt is cleared by a read of the IIR. The special character is transferred to the
RX FIFO.
7.3.1 RX
When software flow control operation is enabled, the SC16IS740/750/760 will compare
incoming data with Xoff1/Xoff2 programmed characters (in certain cases, Xoff1 and Xoff2
must be received sequentially). When the correct Xoff characters are received,
transmission is halted after completing transmission of the current character. Xoff
detection also sets IIR[4] (if enabled via IER[5]) and causes IRQ to go LOW.
To resume transmission, an Xon1/Xon2 character must be received (in certain cases
Xon1 and Xon2 must be received sequentially). When the correct Xon characters are
received, IIR[4] is cleared, and the Xoff interrupt disappears.
7.3.2 TX
Xoff1/Xoff2 character is transmitted when the RX FIFO has passed the HALT trigger level
programmed in TCR[3:0] or the selectable trigger level in FCR[7:6]
Xon1/Xoff2 character is transmitted when the RX FIFO reaches the RESUME trigger level
programmed in TCR[7:4] or RX FIFO falls below the lower selectable trigger level in
FCR[7:6].
The transmission of Xoff/Xon(s) follows the exact same protocol as transmission of an
ordinary character from the FIFO. This means that even if the word length is set to be 5, 6,
or 7 bits, then the 5, 6, or 7 least significant bits of XOFF1/XOFF2 or XON1/XON2 will be
transmitted. (Note that the transmission of 5, 6, or 7 bits of a character is seldom done, but
this functionality is included to maintain compatibility with earlier designs.)
It is assumed that software flow control and hardware flow control will never be enabled
simultaneously. Figure 11 shows an example of software flow control.
SC16IS740_750_760_6 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 06 — 13 May 2008 13 of 62
NXP Semiconductors SC16IS740/750/760
Single UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
Fig 11. Example of software flow control
TRANSMIT FIFO
PARALLEL-TO-SERIAL
SERIAL-TO-PARALLEL
Xon1 WORD
Xon2 WORD
Xoff1 WORD
Xoff2 WORD
RECEIVE FIFO
PARALLEL-TO-SERIAL
SERIAL-TO-PARALLEL
Xon1 WORD
Xon2 WORD
Xoff1 WORD
Xoff2 WORD
UART2UART1
002aaa229
data
Xoff–Xon–Xoff
compare
programmed
Xon-Xoff
characters
SC16IS740_750_760_6 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 06 — 13 May 2008 14 of 62
NXP Semiconductors SC16IS740/750/760
Single UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
7.4 Hardware reset, Power-On Reset (POR) and software reset
These three reset methods are identical and will reset the internal registers as indicated in
Table 4.
Table 4 summarizes the state of register.
[1] Registers DLL, DLH, SPR, XON1, XON2, XOFF1, XOFF2 are not reset by the top-level reset signal
RESET, POR or Software Reset, that is, they hold their initialization values during reset.
[2] This register is not supported in SC16IS740.
[3] Only UART Software Reset bit is supported in this register.
Table 5 summarizes the state of registers after reset.
Table 4. Register reset[1]
Register Reset state
Interrupt Enable Register all bits cleared
Interrupt Identification Register bit 0 is set; all other bits cleared
FIFO Control Register all bits cleared
Line Control Register reset to 0001 1101 (0x1D)
Modem Control Register all bits cleared
Line Status Register bit 5 and bit 6 set; all other bits cleared
Modem Status Register bits 0:3 cleared; bits 4:7 input signals
Enhanced Feature Register all bits cleared
Receiver Holding Register pointer logic cleared
Transmitter Holding Register pointer logic cleared
Transmission Control Register all bits cleared.
Trigger Level Register all bits cleared.
Transmit FIFO level reset to 0100 0000 (0x40)
Receive FIFO level all bits cleared
I/O direction[2] all bits cleared
I/O interrupt enable[2] all bits cleared
I/O control[3] all bits cleared
Extra Feature Register all bits cleared
Table 5. Output signals after reset
Signal Reset state
TX HIGH
RTS HIGH
I/Os inputs
IRQ HIGH by external pull-up
SC16IS740_750_760_6 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 06 — 13 May 2008 15 of 62
NXP Semiconductors SC16IS740/750/760
Single UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
7.5 Interrupts
The SC16IS740/750/760 has interrupt generation and prioritization (seven prioritized
levels of interrupts) capability. The interrupt enable registers (IER and IOIntEna) enable
each of the seven types of interrupts and the IRQ signal in response to an interrupt
generation. When an interrupt is generated, the IIR indicates that an interrupt is pending
and provides the type of interrupt through IIR[5:0]. Table 6 summarizes the interrupt
control functions.
[1] Available only on SC16IS750/SC16IS760.
It is important to note that for the framing error, parity error, and break conditions, LSR[7]
generates the interrupt. LSR[7] is set when there is an error anywhere in the RX FIFO,
and is cleared only when there are no more errors remaining in the FIFO. LSR[4:2] always
represent the error status for the received character at the top of the RX FIFO. Reading
the RX FIFO updates LSR[4:2] to the appropriate status for the new character at the top of
the FIFO. If the RX FIFO is empty, then LSR[4:2] are all zeros.
For the Xoff interrupt, if an Xoff flow character detection caused the interrupt, the interrupt
is cleared by an Xon flow character detection. If a special character detection caused the
interrupt, the interrupt is cleared by a read of the IIR.
Table 6. Summary of interrupt control functions
IIR[5:0] Priority
level Interrupt type Interrupt source
00 0001 none none none
00 0110 1 receiver line status OE, FE, PE, or BI errors occur in characters in the
RX FIFO
00 1100 2 RX time-out Stale data in RX FIFO
00 0100 2 RHR interrupt Receive data ready (FIFO disable) or
RX FIFO above trigger level (FIFO enable)
00 0010 3 THR interrupt Transmit FIFO empty (FIFO disable) or
TX FIFO passes above trigger level (FIFO enable)
00 0000 4 modem status[1] Change of state of modem input pins
11 0000 5 I/O pins[1] Input pins change of state
01 0000 6 Xoff interrupt Receive Xoff character(s)/ special character
10 0000 7 CTS, RTS RTS pin or CTS pin change state from active (LOW)
to inactive (HIGH)
SC16IS740_750_760_6 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 06 — 13 May 2008 16 of 62
NXP Semiconductors SC16IS740/750/760
Single UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
7.5.1 Interrupt mode operation
In Interrupt mode (if any bit of IER[3:0] is 1) the host is informed of the status of the
receiver and transmitter by an interrupt signal, IRQ. Therefore, it is not necessary to
continuously poll the Line Status Register (LSR) to see if any interrupt needs to be
serviced. Figure 12 shows Interrupt mode operation.
7.5.2 Polled mode operation
In Polled mode (IER[3:0] = 0000) the status of the receiver and transmitter can be
checked by polling the Line Status Register (LSR). This mode is an alternative to the FIFO
Interrupt mode of operation where the status of the receiver and transmitter is
automatically known by means of interrupts sent to the CPU. Figure 13 shows FIFO
Polled mode operation.
Fig 12. Interrupt mode operation
1111
IIR
IER
THR RHR
HOST IRQ
002aab042
read IIR
Fig 13. FIFO Polled mode operation
0000
LSR
IER
THR RHR
HOST
read LSR
002aab043
SC16IS740_750_760_6 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 06 — 13 May 2008 17 of 62
NXP Semiconductors SC16IS740/750/760
Single UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
7.6 Sleep mode
Sleep mode is an enhanced feature of the SC16IS740/750/760 UART. It is enabled when
EFR[4], the enhanced functions bit, is set and when IER[4] is set. Sleep mode is entered
when:
The serial data input line, RX, is idle (see Section 7.7 “Break and time-out
conditions”).
The TX FIFO and TX shift register are empty.
There are no interrupts pending except THR.
Remark: Sleep mode will not be entered if there is data in the RX FIFO.
In Sleep mode, the clock to the UART is stopped. Since most registers are clocked using
these clocks, the power consumption is greatly reduced. The UART will wake up when any
change is detected on the RX line, when there is any change in the state of the modem
input pins, or if data is written to the TX FIFO.
Remark: Writing to the divisor latches, DLL and DLH, to set the baud clock, must not be
done during Sleep mode. Therefore, it is advisable to disable Sleep mode using IER[4]
before writing to DLL or DLH.
7.7 Break and time-out conditions
When the UART receives a number of characters and these data are not enough to set off
the receive interrupt (because they do not reach the receive trigger level), the UART will
generate a time-out interrupt instead, 4 character times after the last character is
received. The time-out counter will be reset at the center of each stop bit received or each
time the receive FIFO is read.
A break condition is detected when the RX pin is pulled LOW for a duration longer than
the time it takes to send a complete character plus Start, Stop and Parity bits. A break
condition can be sent by setting LCR[6]. When this happens the TX pin will be pulled LOW
until LSR[6] is cleared by the software.
7.8 Programmable baud rate generator
The SC16IS740/750/760 UART contains a programmable baud rate generator that takes
any clock input and divides it by a divisor in the range between 1 and (216 1). An
additional divide-by-4 prescaler is also available and can be selected by MCR[7], as
shown in Figure 14. The output frequency of the baud rate generator is 16 ×the baud rate.
The formula for the divisor is given in Equation 1:
(1)
where:
prescaler = 1, when MCR[7] is set to ‘0’ after reset (divide-by-1 clock selected)
prescaler = 4, when MCR[7] is set to ‘1’ after reset (divide-by-4 clock selected).
Remark: The default value of prescaler after reset is divide-by-1.
divisor
XTAL1 crystal input frequency
prescaler
-------------------------------------------------------------------------------------


desired baud rate 16×
------------------------------------------------------------------------------------------
=
SC16IS740_750_760_6 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 06 — 13 May 2008 18 of 62
NXP Semiconductors SC16IS740/750/760
Single UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
Figure 14 shows the internal prescaler and baud rate generator circuitry.
DLL and DLH must be written to in order to program the baud rate. DLL and DLH are the
least significant and most significant byte of the baud rate divisor. If DLL and DLH are both
zero, the UART is effectively disabled, as no baud clock will be generated.
Remark: The programmable baud rate generator is provided to select both the transmit
and receive clock rates.
Table 7 and Table 8 show the baud rate and divisor correlation for crystal with frequency
1.8432 MHz and 3.072 MHz, respectively.
Figure 15 shows the crystal clock circuit reference.
Fig 14. Prescaler and baud rate generator block diagram
Table 7. Baud rates using a 1.8432 MHz crystal
Desired baud rate Divisor used to generate
16×clock Percent error difference
between desired and actual
50 2304 0
75 1536 0
110 1047 0.026
134.5 857 0.058
150 768 0
300 384 0
600 192 0
1200 96 0
1800 64 0
2000 58 0.69
2400 48 0
3600 32 0
4800 24 0
7200 16 0
9600 12 0
19200 6 0
38400 3 0
56000 2 2.86
BAUD RATE
GENERATOR
LOGIC
MCR[7] = 1
MCR[7] = 0
PRESCALER
LOGIC
(DIVIDE-BY-1)
INTERNAL
OSCILLATOR
LOGIC
002aaa233
XTAL1
XTAL2 input clock
PRESCALER
LOGIC
(DIVIDE-BY-4)
reference
clock
internal
baud rate
clock for
transmitter
and receiver
SC16IS740_750_760_6 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 06 — 13 May 2008 19 of 62
NXP Semiconductors SC16IS740/750/760
Single UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
Table 8. Baud rates using a 3.072 MHz crystal
Desired baud rate Divisor used to generate
16×clock Percent error difference
between desired and actual
50 2304 0
75 2560 0
110 1745 0.026
134.5 1428 0.034
150 1280 0
300 640 0
600 320 0
1200 160 0
1800 107 0.312
2000 96 0
2400 80 0
3600 53 0.628
4800 40 0
7200 27 1.23
9600 20 0
19200 10 0
38400 5 0
Fig 15. Crystal oscillator circuit reference
002aab402
1.8432 MHz
C1
22 pF C2
33 pF
XTAL1 XTAL2
SC16IS740_750_760_6 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 06 — 13 May 2008 20 of 62
NXP Semiconductors SC16IS740/750/760
Single UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
8. Register descriptions
The programming combinations for register selection are shown in Table 9.
[1] MCR[7] can only be modified when EFR[4] is set.
[2] Accessible only when ERF[4] = 1 and MCR[2] = 1, that is, EFR[4] and MCR[2] are read/write enables.
[3] Available only on SC16IS750/SC16IS760.
[4] Accessible only when LCR[7] is logic 1.
[5] Accessible only when LCR is set to 1011 1111b (0xBF).
Table 9. Register map - read/write properties
Register name Read mode Write mode
RHR/THR Receive Holding Register (RHR) Transmit Holding Register (THR)
IER Interrupt Enable Register (IER) Interrupt Enable Register
IIR/FCR Interrupt Identification Register (IIR) FIFO Control Register (FCR)
LCR Line Control Register (LCR) Line Control Register
MCR Modem Control Register (MCR)[1] Modem Control Register[1]
LSR Line Status Register (LSR) n/a
MSR Modem Status Register (MSR) n/a
SPR Scratchpad Register (SPR) Scratchpad Register
TCR Transmission Control Register (TCR)[2] Transmission Control Register[2]
TLR Trigger Level Register (TLR)[2] Trigger Level Register[2]
TXLVL Transmit FIFO Level Register n/a
RXLVL Receive FIFO Level Register n/a
IODir[3] I/O pin Direction Register I/O pin Direction Register
IOState[3] I/O pin States Register n/a
IOIntEna[3] I/O Interrupt Enable Register I/O Interrupt Enable Register
IOControl[3] I/O pins Control Register I/O pins Control Register
EFCR Extra Features Register Extra Features Register
DLL divisor latch LSB (DLL)[4] divisor latch LSB[4]
DLH divisor latch MSB (DLH)[4] divisor latch MSB[4]
EFR Enhanced Feature Register (EFR)[5] Enhanced Feature Register[5]
XON1 Xon1 word[5] Xon1 word[5]
XON2 Xon2 word[5] Xon2 word[5]
XOFF1 Xoff1 word[5] Xoff1 word[5]
XOFF2 Xoff2 word[5] Xoff2 word[5]
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SC16IS740_750_760_6 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 06 — 13 May 2008 21 of 62
NXP Semiconductors SC16IS740/750/760
Single UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
Table 10. SC16IS740/750/760 internal registers
Register
address Register Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 R/W
General register set[1]
0x00 RHR bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 R
0x00 THR bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 W
0x01 IER CTS
interrupt
enable[2]
RTSinterrupt
enable[2] Xoff[2] Sleep mode[2] modem status
interrupt receive line
status interrupt THR empty
interrupt RX data
available
interrupt
R/W
0x02 FCR RX trigger
level (MSB) RX trigger
level (LSB) TX trigger
level (MSB)[2] TX trigger
level (LSB)[2] reserved[3] TX FIFO
reset[5] RX FIFO
reset[5] FIFO enable W
0x02 IIR[6] FIFO enable FIFO enable interrupt
priority bit 4[2] interrupt
priority bit 3[2] interrupt
priority bit 2 interrupt
priority bit 1 interrupt
priority bit 0 interrupt status R
0x03 LCR DivisorLatch
Enable set break set parity even parity parity enable stop bit word length
bit 1 word length
bit 0 R/W
0x04 MCR clock
divisor[2] IrDA mode
enable[2] Xon Any[2] loopback
enable reserved[3] TCR and TLR
enable[2] RTS DTR/(IO5)[4] R/W
0x05 LSR FIFO data
error THR and
TSR empty THR empty break interrupt framing error parity error overrun error data in receiver R
0x06 MSR CD/(IO6)[4] RI/(IO7)[4] DSR/ (IO4)[4] CTS CD/ (IO6)[4] RI/(IO7)[4] DSR/ (IO4)[4] CTS R
0x07 SPR bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 R/W
0x06 TCR[7] bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 R/W
0x07 TLR[7] bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 R/W
0x08 TXLVL bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 R
0x09 RXLVL bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 R
0x0A IODir[4] bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 R/W
0x0B IOState[4] bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 R/W
0x0C IOIntEna[4] bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 R/W
0x0D reserved[3] reserved[3] reserved[3] reserved[3] reserved[3] reserved[3] reserved[3] reserved[3] reserved[3]
0x0E IOControl[4] reserved[3] reserved[3] reserved[3] reserved[3] UART
software reset reserved[3] I/O[7:4] or RI,
CD, DTR, DSR latch R/W
0x0F EFCR IrDA mode
(slow/ fast)[8] reserved[3] auto RS-485
RTS output
inversion
auto RS-485
RTS direction
control
reserved[3] transmitter
disable receiver
disable 9-bit mode
enable R/W
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SC16IS740_750_760_6 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 06 — 13 May 2008 22 of 62
NXP Semiconductors SC16IS740/750/760
Single UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
[1] These registers are accessible only when LCR[7] = 0.
[2] These bits in can only be modified if register bit EFR[4] is enabled.
[3] These bits are reserved and should be set to 0.
[4] Only available on the SC16IS750/SC16IS760.
[5] After Receive FIFO or Transmit FIFO reset (through FCR[1:0]), the user must wait at least 2 ×Tclk of XTAL1 before reading or writing data to RHR and THR, respectively.
[6] Burst reads on the serial interface (that is, reading multiple elements on the I2C-bus without a STOP or repeated START condition, or reading multiple elements on the SPI bus
without de-asserting the CS pin), should not be performed on the IIR register.
[7] These registers are accessible only when MCR[2] = 1 and EFR[4] = 1.
[8] IrDA mode slow/fast for SC16IS760, slow only for SC16IS750.
[9] The special register set is accessible only when LCR[7] = 1 and not 0xBF.
[10] Enhanced Feature Registers are only accessible when LCR = 0xBF.
Special register set[9]
0x00 DLL bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 R/W
0x01 DLH bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 R/W
Enhanced register set[10]
0x02 EFR Auto CTS Auto RTS special
character
detect
enable
enhanced
functions
software flow
control bit 3 software flow
control bit 2 software flow
control bit 1 software flow
control bit 0 R/W
0x04 XON1 bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 R/W
0x05 XON2 bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 R/W
0x06 XOFF1 bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 R/W
0x07 XOFF2 bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 R/W
Table 10. SC16IS740/750/760 internal registers
…continued
Register
address Register Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 R/W
SC16IS740_750_760_6 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 06 — 13 May 2008 23 of 62
NXP Semiconductors SC16IS740/750/760
Single UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
8.1 Receive Holding Register (RHR)
The receiver section consists of the Receiver Holding Register (RHR) and the Receiver
Shift Register (RSR). The RHR is actually a 64-byte FIFO. The RSR receives serial data
from the RX pin. The data is converted to parallel data and moved to the RHR. The
receiver section is controlled by the Line Control Register. If the FIFO is disabled, location
zero of the FIFO is used to store the characters.
8.2 Transmit Holding Register (THR)
The transmitter section consists of the Transmit Holding Register (THR) and the Transmit
Shift Register (TSR). The THR is actually a 64-byte FIFO. The THR receives data and
shifts it into the TSR, where it is converted to serial data and moved out on the TX pin. If
the FIFO is disabled, the FIFO is still used to store the byte. Characters are lost if overflow
occurs.
8.3 FIFO Control Register (FCR)
This is a write-only register that is used for enabling the FIFOs, clearing the FIFOs, setting
transmitter and receiver trigger levels. Table 11 shows FIFO Control Register bit settings.
Table 11. FIFO Control Register bits description
Bit Symbol Description
7:6 FCR[7](MSB),
FCR[6] (LSB) RX trigger. Sets the trigger level for the RX FIFO.
00 = 8 characters
01 = 16 characters
10 = 56 characters
11 = 60 characters
5:4 FCR[5](MSB),
FCR[4] (LSB) TX trigger. Sets the trigger level for the TX FIFO.
00 = 8 spaces
01 = 16 spaces
10 = 32 spaces
11 = 56 spaces
FCR[5:4] can only be modified and enabled when EFR[4] is set. This is
because the transmit trigger level is regarded as an enhanced function.
3 FCR[3] reserved
2 FCR[2][1] reset TX FIFO
logic 0 = no FIFO transmit reset (normal default condition)
logic 1 = clears the contents of the transmit FIFO and resets the FIFO
level logic (the Transmit Shift Register is not cleared or altered). This bit
will return to a logic 0 after clearing the FIFO.
1 FCR[1][1] reset RX FIFO
logic 0 = no FIFO receive reset (normal default condition)
logic 1 = clears the contents of the receive FIFO and resets the FIFO
level logic (the Receive Shift Register is not cleared or altered). This bit
will return to a logic 0 after clearing the FIFO.
0 FCR[0] FIFO enable
logic 0 = disable the transmit and receive FIFO (normal default condition)
logic 1 = enable the transmit and receive FIFO
SC16IS740_750_760_6 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 06 — 13 May 2008 24 of 62
NXP Semiconductors SC16IS740/750/760
Single UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
[1] FIFO reset requires at least two XTAL1 clocks, therefore, they cannot be reset without the presence of the
XTAL1 clock.
8.4 Line Control Register (LCR)
This register controls the data communication format. The word length, number of stop
bits, and parity type are selected by writing the appropriate bits to the LCR. Table 12
shows the Line Control Register bit settings.
Table 12. Line Control Register bits description
Bit Symbol Description
7 LCR[7] divisor latch enable
logic 0 = divisor latch disabled (normal default condition)
logic 1 = divisor latch enabled
6 LCR[6] Break control bit. When enabled, the break control bit causes a break
condition to be transmitted (the TX output is forced to a logic 0 state).
This condition exists until disabled by setting LCR[6] to a logic 0.
logic 0 = no TX break condition (normal default condition).
logic 1 = forces the transmitter output (TX) to a logic 0 to alert the
communication terminal to a line break condition
5 LCR[5] Set parity. LCR[5] selects the forced parity format (if LCR[3] = 1).
logic 0 = parity is not forced (normal default condition).
LCR[5] = logic 1 and LCR[4] = logic 0: parity bit is forced to a logical 1
for the transmit and receive data.
LCR[5] = logic 1 and LCR[4] = logic 1: parity bit is forced to a logical 0
for the transmit and receive data.
4 LCR[4] parity type select
logic 0 = odd parity is generated (if LCR[3] = 1)
logic 1 = even parity is generated (if LCR[3] = 1)
3 LCR[3] parity enable
logic 0 = no parity (normal default condition).
logic 1 = a parity bit is generated during transmission and the receiver
checks for received parity
2 LCR[2] Number of stop bits. Specifies the number of stop bits.
0 to 1 stop bit (word length = 5, 6, 7, 8)
1 to 1.5 stop bits (word length = 5)
1 = 2 stop bits (word length = 6, 7, 8)
1:0 LCR[1:0] Word length bits 1, 0. These two bits specify the word length to be
transmitted or received; see Table 15.
SC16IS740_750_760_6 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 06 — 13 May 2008 25 of 62
NXP Semiconductors SC16IS740/750/760
Single UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
Table 13. LCR[5] parity selection
LCR[5] LCR[4] LCR[3] Parity selection
X X 0 no parity
0 0 1 odd parity
0 1 1 even parity
1 0 1 forced parity ‘1’
1 1 1 forced parity ‘0’
Table 14. LCR[2] stop bit length
LCR[2] Word length (bits) Stop bit length (bit times)
0 5, 6, 7, 8 1
15 1
12
1 6, 7, 8 2
Table 15. LCR[1:0] word length
LCR[1] LCR[0] Word length (bits)
005
016
107
118
SC16IS740_750_760_6 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 06 — 13 May 2008 26 of 62
NXP Semiconductors SC16IS740/750/760
Single UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
8.5 Line Status Register (LSR)
Table 16 shows the Line Status Register bit settings.
When the LSR is read, LSR[4:2] reflect the error bits (BI, FE, PE) of the character at the
top of the RX FIFO (next character to be read). Therefore, errors in a character are
identified by reading the LSR and then reading the RHR.
LSR[7] is set when there is an error anywhere in the RX FIFO, and is cleared only when
there are no more errors remaining in the FIFO.
Table 16. Line Status Register bits description
Bit Symbol Description
7 LSR[7] FIFO data error.
logic 0 = no error (normal default condition)
logic 1 = at least one parity error, framing error, or break indication is in the
receiver FIFO. This bit is cleared when no more errors are present in the
FIFO.
6 LSR[6] THR and TSR empty. This bit is the Transmit Empty indicator.
logic 0 = transmitter hold and shift registers are not empty
logic 1 = transmitter hold and shift registers are empty
5 LSR[5] THR empty. This bit is the Transmit Holding Register Empty indicator.
logic 0 = transmit hold register is not empty
logic 1 = transmit hold register is empty. The host can now load up to
64 characters of data into the THR if the TX FIFO is enabled.
4 LSR[4] break interrupt
logic 0 = no break condition (normal default condition)
logic 1 = a break condition occurred and associated character is 0x00, that
is, RX was LOW for one character time frame
3 LSR[3] framing error
logic0=noframing error in data being read from RX FIFO (normal default
condition).
logic 1 = framing error occurred in data being read from RX FIFO, that is,
received data did not have a valid stop bit
2 LSR[2] parity error.
logic 0 = no parity error (normal default condition)
logic 1 = parity error in data being read from RX FIFO
1 LSR[1] overrun error
logic 0 = no overrun error (normal default condition)
logic 1 = overrun error has occurred
0 LSR[0] data in receiver
logic 0 = no data in receive FIFO (normal default condition)
logic 1 = at least one character in the RX FIFO
SC16IS740_750_760_6 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 06 — 13 May 2008 27 of 62
NXP Semiconductors SC16IS740/750/760
Single UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
8.6 Modem Control Register (MCR)
The MCR controls the interface with the mode, data set, or peripheral device that is
emulating the modem. Table 17 shows the Modem Control Register bit settings.
[1] MCR[7:5] and MCR[2] can only be modified when EFR[4] is set, that is, EFR[4] is a write enable.
[2] Only available on SC16IS750/SC16IS760.
Table 17. Modem Control Register bits description
Bit Symbol Description
7 MCR[7][1] clock divisor
logic 0 = divide-by-1 clock input
logic 1 = divide-by-4 clock input
6 MCR[6][1] IrDA mode enable
logic 0 = normal UART mode
logic 1 = IrDA mode
5 MCR[5][1] Xon Any
logic 0 = disable Xon Any function
logic 1 = enable Xon Any function
4 MCR[4] enable loopback
logic 0 = normal operating mode
logic 1 = enable local Loopback mode (internal). In this mode the
MCR[1:0] signals are looped back into MSR[4:5] and the TX output is
looped back to the RX input internally.
3 MCR[3] reserved
2 MCR[2] TCR and TLR enable
logic 0 = disable the TCR and TLR register.
logic 1 = enable the TCR and TLR register.
1 MCR[1] RTS
logic 0 = force RTS output to inactive (HIGH)
logic 1 = force RTS output to active (LOW). In Loopback mode,
controls MSR[4]. If Auto RTS is enabled, the RTS output is controlled
by hardware flow control.
0 MCR[0] DTR[2]. If GPIO5 is selected as DTR modem pin through IOControl
register bit 1, the state of DTR pin can be controlled as below. Writing to
IOState bit 5 will not have any effect on this pin.
logic 0 = Force DTR output to inactive (HIGH)
logic 1 = Force DTR output to active (LOW)
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Product data sheet Rev. 06 — 13 May 2008 28 of 62
NXP Semiconductors SC16IS740/750/760
Single UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
8.7 Modem Status Register (MSR)
This 8-bit register provides information about the current state of the control lines from the
modem, data set, or peripheral device to the host. It also indicates when a control input
from the modem changes state. Table 18 shows Modem Status Register bit settings.
[1] Only available on SC16IS750/SC16IS760.
Remark: The primary inputs RI, CD, CTS, DSR are all active LOW.
Table 18. Modem Status Register bits description
Bit Symbol Description
7 MSR[7] CD[1] (active HIGH, logical 1). If GPIO6 is selected as CD modem pin
through IOControl register bit 1, the state of CD pin can be read from this
bit. This bit is the complement of the CD input. Reading IOState bit 6 does
not reflect the true state of CD pin.
6 MSR[6] RI[1] (active HIGH, logical 1). If GPIO7 is selected as RI modem pin through
IOControl register bit 1, the state of RI pin can be read from this bit. This bit
is the complement of the RI input. Reading IOState bit 6 does not reflect the
true state of RI pin.
5 MSR[5] DSR[1] (active HIGH, logical 1). If GPIO4 is selected as DSR modem pin
through IOControl register bit 1, the state of DSR pin can be read from this
bit. This bit is the complement of the DSR input. Reading IOState bit 4 does
not reflect the true state of DSR pin.
4 MSR[4] CTS (active HIGH, logical 1). This bit is the complement of the CTS input.
3 MSR[3] CD[1]. Indicates that CD input has changed state. Cleared on a read.
2 MSR[2] RI[1]. Indicates that RI input has changed state from LOW to HIGH.
Cleared on a read.
1 MSR[1] DSR[1]. Indicates that DSR input has changed state. Cleared on a read.
0 MSR[0] CTS. Indicates that CTS input has changed state. Cleared on a read.
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NXP Semiconductors SC16IS740/750/760
Single UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
8.8 Interrupt Enable Register (IER)
The Interrupt Enable Register (IER) enables each of the six types of interrupt, receiver
error, RHR interrupt, THR interrupt, modem status, Xoff received, or CTS/RTS change of
state from LOW to HIGH. The IRQ output signal is activated in response to interrupt
generation. Table 19 shows the Interrupt Enable Register bit settings.
[1] IER[7:4] can only be modified if EFR[4] is set, that is, EFR[4] is a write enable. Re-enabling IER[1] will not
cause a new interrupt if the THR is below the threshold.
[2] Only available on the SC16IS750/SC16IS760.
Table 19. Interrupt Enable Register bits description
Bit Symbol Description
7 IER[7][1] CTS interrupt enable
logic 0 = disable the CTS interrupt (normal default condition)
logic 1 = enable the CTS interrupt
6 IER[6][1] RTS interrupt enable
logic 0 = disable the RTS interrupt (normal default condition)
logic 1 = enable the RTS interrupt
5 IER[5][1] Xoff interrupt
logic 0 = disable the Xoff interrupt (normal default condition)
logic 1 = enable the Xoff interrupt
4 IER[4][1] Sleep mode
logic 0 = disable Sleep mode (normal default condition)
logic 1 = enable Sleep mode. See Section 7.6 “Sleep mode” for details.
3 IER[3] Modem Status Interrupt[2].
logic 0 = disable the modem status register interrupt (normal default
condition)
logic 1 = enable the modem status register interrupt
Remark: See IOControl register bit 1 in Table 30 for the description of how to
program the pins as modem pins.
2 IER[2] Receive Line Status interrupt
logic 0 = disable the receiver line status interrupt (normal default condition)
logic 1 = enable the receiver line status interrupt
1 IER[1] Transmit Holding Register interrupt.
logic 0 = disable the THR interrupt (normal default condition)
logic 1 = enable the THR interrupt
0 IER[0] Receive Holding Register interrupt.
logic 0 = disable the RHR interrupt (normal default condition)
logic 1 = enable the RHR interrupt
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Product data sheet Rev. 06 — 13 May 2008 30 of 62
NXP Semiconductors SC16IS740/750/760
Single UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
8.9 Interrupt Identification Register (IIR)
The IIR is a read-only 8-bit register which provides the source of the interrupt in a
prioritized manner. Table 20 shows Interrupt Identification Register bit settings.
[1] Modem interrupt status must be read via MSR register and GPIO interrupt status must be read via IOState
register.
[2] Only available on SC16IS750/SC16IS760.
Table 20. Interrupt Identification Register bits description
Bit Symbol Description
7:6 IIR[7:6] mirror the contents of FCR[0]
5:1 IIR[5:1] 5-bit encoded interrupt. See Table 21.
0 IIR[0] interrupt status
logic 0 = an interrupt is pending
logic 1 = no interrupt is pending
Table 21. Interrupt source
Priority
level IIR[5] IIR[4] IIR[3] IIR[2] IIR[1] IIR[0] Source of the interrupt
1 0 0 0 1 1 0 Receiver Line Status error
2 0 0 1 1 0 0 Receiver time-out interrupt
2 0 0 0 1 0 0 RHR interrupt
3 0 0 0 0 1 0 THR interrupt
4 0 0 0 0 0 0 modem interrupt[1][2]
5 1 1 0 0 0 0 input pin change of state[1][2]
6 0 1 0 0 0 0 received Xoff signal/
special character
7 100000CTS, RTS change of state
from active (LOW) to inactive
(HIGH)
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NXP Semiconductors SC16IS740/750/760
Single UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
8.10 Enhanced Features Register (EFR)
This 8-bit register enables or disables the enhanced features of the UART. Table 22 shows
the enhanced feature register bit settings.
8.11 Division registers (DLL, DLH)
These are two 8-bit registers which store the 16-bit divisor for generation of the baud clock
in the baud rate generator. DLH stores the most significant part of the divisor. DLL stores
the least significant part of the divisor.
Remark: DLL and DLH can only be written to before Sleep mode is enabled, that is,
before IER[4] is set.
Table 22. Enhanced Features Register bits description
Bit Symbol Description
7 EFR[7] CTS flow control enable
logic 0 = CTS flow control is disabled (normal default condition)
logic 1 = CTS flow control is enabled. Transmission will stop when a HIGH
signal is detected on the CTS pin.
6 EFR[6] RTS flow control enable.
logic 0 = RTS flow control is disabled (normal default condition)
logic 1 = RTS flow control is enabled. The RTS pin goes HIGH when the
receiver FIFO halt trigger level TCR[3:0] is reached, and goes LOW when
the receiver FIFO resume transmission trigger level TCR[7:4] is reached.
5 EFR[5] Special character detect
logic 0 = Special character detect disabled (normal default condition)
logic 1 = Special character detect enabled. Received data is compared
with Xoff2 data. If a match occurs, the received data is transferred to FIFO
and IIR[4] is set to a logical 1 to indicate a special character has been
detected.
4 EFR[4] Enhanced functions enable bit
logic 0 = disables enhanced functions and writing to IER[7:4], FCR[5:4],
MCR[7:5].
logic 1 = enables the enhanced function IER[7:4], FCR[5:4], and MCR[7:5]
so that they can be modified.
3:0 EFR[3:0] Combinations of software flow control can be selected by programming these
bits. See Table 3 “Software flow control options (EFR[3:0])”.
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NXP Semiconductors SC16IS740/750/760
Single UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
8.12 Transmission Control Register (TCR)
This 8-bit register is used to store the RX FIFO threshold levels to stop/start transmission
during hardware/software flow control. Table 23 shows Transmission Control Register bit
settings.
TCR trigger levels are available from 0 to 60 characters with a granularity of four.
Remark: TCR can only be written to when EFR[4] = 1 and MCR[2] = 1. The programmer
must program the TCR such that TCR[3:0] > TCR[7:4]. There is no built-in hardware
check to make sure this condition is met. Also, the TCR must be programmed with this
condition before auto RTS or software flow control is enabled to avoid spurious operation
of the device.
8.13 Trigger Level Register (TLR)
This 8-bit register is used to store the transmit and received FIFO trigger levels used for
interrupt generation. Trigger levels from 4 to 60 can be programmed with a granularity
of 4. Table 24 shows trigger level register bit settings.
Remark: TLR can only be written to when EFR[4] = 1 and MCR[2] = 1. If TLR[3:0] or
TLR[7:4] are logical 0, the selectable trigger levels via the FIFO Control Register (FCR)
are used for the transmit and receive FIFO trigger levels. Trigger levels from 4 characters
to 60 characters are available with a granularity of four. The TLR should be programmed
for N4, where N is the desired trigger level.
When the trigger level setting in TLR is zero, the SC16IS740/750/760 uses the trigger
level setting defined in FCR. If TLR has non-zero trigger level value, the trigger level
defined in FCR is discarded. This applies to both transmit FIFO and receive FIFO trigger
level setting.
When TLR is used for RX trigger level control, FCR[7:6] should be left at the default state,
that is, ‘00’.
8.14 Transmitter FIFO Level register (TXLVL)
This register is a read-only register, it reports the number of spaces available in the
transmit FIFO.
Table 23. Transmission Control Register bits description
Bit Symbol Description
7:4 TCR[7:4] RX FIFO trigger level to resume
3:0 TCR[3:0] RX FIFO trigger level to halt transmission
Table 24. Trigger Level Register bits description
Bit Symbol Description
7:4 TLR[7:4] RX FIFO trigger levels (4 to 60), number of characters available.
3:0 TLR[3:0] TX FIFO trigger levels (4 to 60), number of spaces available.
Table 25. Transmitter FIFO Level register bits description
Bit Symbol Description
7 - not used; set to zeros
6:0 TXLVL[6:0] number of spaces available in TX FIFO, from 0 (0x00) to 64 (0x40)
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NXP Semiconductors SC16IS740/750/760
Single UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
8.15 Receiver FIFO Level register (RXLVL)
This register is a read-only register, it reports the fill level of the receive FIFO. That is, the
number of characters in the RX FIFO.
8.16 Programmable I/O pins Direction register (IODir)
This register is only available on the SC16IS750 and SC16IS760. This register is used to
program the I/O pins direction. Bit 0 to bit 7 controls GPIO0 to GPIO7.
Remark: If there is a pending input (GPIO) interrupt and IODir is written, this pending
interrupt will be cleared, that is, the interrupt signal will be negated.
8.17 Programmable I/O pins State Register (IOState)
This register is only available on the SC16IS750 and SC16IS760. When ‘read’, this
register returns the actual state of all I/O pins. When ‘write’, each register bit will be
transferred to the corresponding IO pin programmed as output.
8.18 I/O Interrupt Enable Register (IOIntEna)
This register is only available on the SC16IS750 and SC16IS760. This register enables
the interrupt due to a change in the I/O configured as inputs. If GPIO[7:4] are programmed
as modem pins, their interrupt generation must be enabled via IER register bit 3. In this
case bit 7 to bit 4 of IOIntEna will have no effect on GPIO[7:4].
Table 26. Receiver FIFO Level register bits description
Bit Symbol Description
7 - not used; set to zeros
6:0 RXLVL[6:0] number of characters stored in RX FIFO, from 0 (0x00) to 64 (0x40)
Table 27. IODir register bits description
Bit Symbol Description
7:0 IODir set GPIO pins [7:0] to input or output
0 = input
1 = output
Table 28. IOState register bits description
Bit Symbol Description
7:0 IOState Write this register:
set the logic level on the output pins
0 = set output pin to zero
1 = set output pin to one
Read this register:
return states of all pins
Table 29. IOIntEna register bits description
Bit Symbol Description
7:0 IOIntEna input interrupt enable
0 = a change in the input pin will not generate an interrupt
1 = a change in the input will generate an interrupt
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NXP Semiconductors SC16IS740/750/760
Single UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
8.19 I/O Control register (IOControl)
This register is only available on the SC16IS750 and SC16IS760.
Remark: As I/O pins, the direction, state, and interrupt of GPIO4 to GPIO7 are controlled
by the following registers: IODir, IOState, IOIntEna, and IOControl. The state of CD, RI,
DSR pins will not be reflected in MSR[7:5] or MSR[3:1], and any change of state on these
three pins will not trigger a modem status interrupt (even if enabled via IER[3]), and the
state of the DTR pin cannot be controlled by MCR[0].
As modem CD, RI, DSR pins, the status at the input of these three pins can be read from
MSR[7:5] and MSR[3:1], and the state of DTR pin can be controlled by MCR[0]. Also, if
modem status interrupt bit is enabled, IER[3], a change of state of RI, CD, DSR pins will
trigger a modem interrupt. Bit[7:4] of the IODir, IOState, and IOIntEna registers will not
have any effect on these three pins.
Table 30. IOControl register bits description
Bit Symbol Description
7:4 - reserved for future use
3 SRESET software reset
A write to bit will reset the device. Once the device is reset this bit is
automatically set to ‘0’
2 - reserved for future use
1 GPIO[7:4] or
modem pins This bit programs GPIO[7:4] as I/O pins or modem RI, CD, DTR, DSR
pins.
0 = GPIO[7:4] behave as I/O pins
1 = GPIO[7:4] behave as RI, CD, DTR, DSR
0 IOLATCH enable/disable inputs latching
0 = input values are not latched. A change in any input generates an
interrupt. A read of the input register clears the interrupt. If the input
goes back to its initial logic state before the input register is read,
then the interrupt is cleared.
1 = input values are latched. A change in the input generates an
interrupt and the input logic value is loaded in the bit of the
corresponding input state register (IOState). A read of the IOState
register clears the interrupt. If the input pin goes back to its initial
logic state before the interrupt register is read, then the interrupt is
not cleared and the corresponding bit of the IOState register keeps
the logic value that initiates the interrupt.
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Product data sheet Rev. 06 — 13 May 2008 35 of 62
NXP Semiconductors SC16IS740/750/760
Single UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
8.20 Extra Features Control Register (EFCR)
[1] For SC16IS760 only.
9. RS-485 features
9.1 Auto RS-485 RTS control
Normally the RTS pin is controlled by MCR bit 1, or if hardware flow control is enabled, the
logic state of the RTS pin is controlled by the hardware flow control circuitry. EFCR
register bit 4 will take the precedence over the other two modes; once this bit is set, the
transmitter will control the state of the RTS pin. The transmitter automatically asserts the
RTS pin (logic 0) once the host writes data to the transmit FIFO, and deasserts RTS pin
(logic 1) once the last bit of the data has been transmitted.
To use the auto RS-485 RTS mode the software would have to disable the hardware flow
control function.
Table 31. Extra Features Control Register bits description
Bit Symbol Description
7 IRDA MODE IrDA mode
0 = IrDA SIR, 316 pulse ratio, data rate up to 115.2 kbit/s
1 = IrDA SIR, 14 pulse ratio, data rate up to 1.152 Mbit/s[1]
6 - reserved
5 RTSINVER invert RTS signal in RS-485 mode
0: RTS = 0 during transmission and RTS = 1 during reception
1: RTS = 1 during transmission and RTS = 0 during reception
4 RTSCON enable the transmitter to control the RTS pin
0 = transmitter does not control RTS pin
1 = transmitter controls RTS pin
3 - reserved
2 TXDISABLE Disable transmitter. UART does not send serial data out on the
transmit pin, but the transmit FIFO will continue to receive data from
host until full. Any data in the TSR will be sent out before the
transmitter goes into disable state.
0: transmitter is enabled
1: transmitter is disabled
1 RXDISABLE Disable receiver. UART will stop receiving data immediately once this
bit set to a 1, and any data in the TSR will be sent to the receive FIFO.
User is advised not to set this bit during receiving.
0: receiver is enabled
1: receiver is disabled
0 9-BIT MODE Enable 9-bit or Multidrop mode (RS-485).
0: normal RS-232 mode
1: enables RS-485 mode
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NXP Semiconductors SC16IS740/750/760
Single UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
9.2 RS-485 RTS output inversion
EFCR bit 5 reverses the polarity of the RTS pin if the UART is in auto RS-485 RTS mode.
When the transmitter has data to be sent it will deasserts the RTS pin (logic 1), and when
the last bit of the data has been sent out the transmitter asserts the RTS pin (logic 0).
9.3 Auto RS-485
EFCR bit 0 is used to enable the RS-485 mode (multidrop or 9-bit mode). In this mode of
operation, a ‘master’ station transmits an address character followed by data characters
for the addressed ‘slave’ stations. The slave stations examine the received data and
interrupt the controller if the received character is an address character (parity bit = 1).
To use the auto RS-485 mode the software would have to disable the hardware and
software flow control functions.
9.3.1 Normal multidrop mode
The 9-bit Mode in EFCR (bit 0) is enabled, but not Special Character Detect (EFR bit 5).
The receiver is set to Force Parity 0 (LCR[5:3] = 111) in order to detect address bytes.
With the receiver initially disabled, it ignores all the data bytes (parity bit = 0) until an
address byte is received (parity bit = 1). This address byte will cause the UART to set the
parity error. The UART will generate a line status interrupt (IER bit 2 must be set to ‘1’ at
this time), and at the same time puts this address byte in the RX FIFO. After the controller
examines the byte it must make a decision whether or not to enable the receiver; it should
enable the receiver if the address byte addresses its ID address, and must not enable the
receiver if the address byte does not address its ID address.
If the controller enables the receiver, the receiver will receive the subsequent data until
being disabled by the controller after the controller has received a complete message from
the ‘master’ station. If the controller does not disable the receiver after receiving a
message from the ‘master’ station, the receiver will generate a parity error upon receiving
another address byte. The controller then determines if the address byte addresses its ID
address, if it is not, the controller then can disable the receiver. If the address byte
addresses the ‘slave’ ID address, the controller take no further action, the receiver will
receive the subsequent data.
9.3.2 Auto address detection
If Special Character Detect is enabled (EFR[5] is set and the XOFF2 register contains the
address byte) the receiver will try to detect an address byte that matches the programmed
character in the XOFF2 register. If the received byte is a data byte or an address byte that
does not match the programmed character in the XOFF2 register, the receiver will discard
these data. Upon receiving an address byte that matches the Xoff2 character, the receiver
will be automatically enabled if not already enabled, and the address character is pushed
into the RX FIFO along with the parity bit (in place of the parity error bit). The receiver also
generates a line status interrupt (IER[2] must be set to ‘1’ at this time). The receiver will
then receive the subsequent data from the ‘master’ station until being disabled by the
controller after having received a message from the ‘master’ station.
If another address byte is received and this address byte does not match Xoff2 character,
the receiver will be automatically disabled and the address byte is ignored. If the address
byte matches Xoff2 character, the receiver will put this byte in the RX FIFO along with the
parity bit in the parity error bit (LSR bit 2).
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NXP Semiconductors SC16IS740/750/760
Single UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
10. I2C-bus operation
The two lines of the I2C-bus are a serial data line (SDA) and a serial clock line (SCL). Both
lines are connected to a positive supply via a pull-up resistor, and remain HIGH when the
bus is not busy. Each device is recognized by a unique address whether it is a
microcomputer, LCD driver, memory or keyboard interface and can operate as either a
transmitter or receiver, depending on the function of the device. A device generating a
message or data is a transmitter, and a device receiving the message or data is a
receiver. Obviously, a passive function like an LCD driver could only be a receiver, while a
microcontroller or a memory can both transmit and receive data.
10.1 Data transfers
One data bit is transferred during each clock pulse (see Figure 16). The data on the SDA
line must remain stable during the HIGH period of the clock pulse in order to be valid.
Changes in the data line at this time will be interpreted as control signals. A HIGH-to-LOW
transition of the data line (SDA) while the clock signal (SCL) is HIGH indicates a START
condition, and a LOW-to-HIGH transition of the SDA while SCL is HIGH defines a STOP
condition (see Figure 17). The bus is considered to be busy after the START condition and
free again at a certain time interval after the STOP condition. The START and STOP
conditions are always generated by the master.
The number of data bytes transferred between the START and STOP condition from
transmitter to receiver is not limited. Each byte, which must be eight bits long, is
transferred serially with the most significant bit first, and is followed by an acknowledge bit
(see Figure 18). The clock pulse related to the acknowledge bit is generated by the
master. The device that acknowledges has to pull down the SDA line during the
acknowledge clock pulse, while the transmitting device releases this pulse (see
Figure 19).
Fig 16. Bit transfer on the I2C-bus
Fig 17. START and STOP conditions
mba607
data line
stable;
data valid
change
of data
allowed
SDA
SCL
mba608
SDA
SCL P
STOP condition
SDA
SCL
S
START condition
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NXP Semiconductors SC16IS740/750/760
Single UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
A slave receiver must generate an acknowledge after the reception of each byte, and a
master must generate one after the reception of each byte clocked out of the slave
transmitter.
There are two exceptions to the ‘acknowledge after every byte’ rule. The first occurs when
a master is a receiver: it must signal an end of data to the transmitter by not signalling an
acknowledge on the last byte that has been clocked out of the slave. The acknowledge
related clock, generated by the master should still take place, but the SDA line will not be
pulled down. In order to indicate that this is an active and intentional lack of
acknowledgement, we shall term this special condition as a ‘negative acknowledge’.
The second exception is that a slave will send a negative acknowledge when it can no
longer accept additional data bytes. This occurs after an attempted transfer that cannot be
accepted.
10.2 Addressing and transfer formats
Each device on the bus has its own unique address. Before any data is transmitted on the
bus, the master transmits on the bus the address of the slave to be accessed for this
transaction. A well-behaved slave with a matching address, if it exists on the network,
should of course acknowledge the master's addressing. The addressing is done by the
first byte transmitted by the master after the START condition.
Fig 18. Data transfer on the I2C-bus
S P
SDA
SCL
MSB
0 1 6 7 8 0 1 2 to 7 8
ACK ACK
002aab012
START
condition STOP
condition
acknowledgement signal
from receiver
byte complete,
interrupt within receiver clock line held LOW
while interrupt is serviced
Fig 19. Acknowledge on the I2C-bus
S01 678
002aab013
data output
by transmitter
data output
by receiver
SCL from master
START
condition
transmitter stays off of the bus
during the acknowledge clock
acknowledgement signal
from receiver
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NXP Semiconductors SC16IS740/750/760
Single UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
An address on the network is seven bits long, appearing as the most significant bits of the
address byte. The last bit is a direction (R/W) bit. A ‘0’ indicates that the master is
transmitting (write) and a ‘1’ indicates that the master requests data (read). A complete
data transfer, comprised of an address byte indicating a ‘write’ and two data bytes is
shown in Figure 20.
When an address is sent, each device in the system compares the first seven bits after the
START with its own address. If there is a match, the device will consider itself addressed
by the master, and will send an acknowledge. The device could also determine if in this
transaction it is assigned the role of a slave receiver or slave transmitter, depending on the
R/W bit.
Each node of the I2C-bus network has a unique seven-bit address. The address of a
microcontroller is of course fully programmable, while peripheral devices usually have
fixed and programmable address portions.
When the master is communicating with one device only, data transfers follow the format
of Figure 20, where the R/W bit could indicate either direction. After completing the
transfer and issuing a STOP condition, if a master would like to address some other
device on the network, it could start another transaction by issuing a new START.
Another way for a master to communicate with several different devices would be by using
a ‘repeated START’. After the last byte of the transaction was transferred, including its
acknowledge (or negative acknowledge), the master issues another START, followed by
address byte and data—without effecting a STOP. The master may communicate with a
number of different devices, combining ‘reads’ and ‘writes’. After the last transfer takes
place, the master issues a STOP and releases the bus. Possible data formats are
demonstrated in Figure 21. Note that the repeated START allows for both change of a
slave and a change of direction, without releasing the bus. We shall see later on that the
change of direction feature can come in handy even when dealing with a single device.
In a single master system, the repeated START mechanism may be more efficient than
terminating each transfer with a STOP and starting again. In a multimaster environment,
the determination of which format is more efficient could be more complicated, as when a
master is using repeated STARTs it occupies the bus for a long time and thus preventing
other devices from initiating transfers.
Fig 20. A complete data transfer
S P
SDA
SCL 0 to 6 78
ACK
002aab046
START
condition STOP
condition
address R/W
0 to 6 78
data ACK
0 to 6 78
data ACK
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NXP Semiconductors SC16IS740/750/760
Single UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
Fig 21. I2C-bus data formats
002aab458
DATASLAVE ADDRESSmaster write: S W A DATAA A P
data transferred
(n bytes + acknowledge)
START condition
STOP condition
acknowledge acknowledge acknowledgewrite
DATASLAVE ADDRESSmaster read: S R A DATAA NA P
data transferred
(n bytes + acknowledge)
START condition
STOP condition
acknowledge acknowledge not
acknowledge
read
DATASLAVE ADDRESS
combined
formats: S R/W A DATAA A P
data transferred
(n bytes + acknowledge)
START condition
STOP condition
acknowledge acknowledge acknowledgeread or
write
SLAVE ADDRESSSr R/W A
repeated
START condition acknowledgeread or
write
direction of transfer
may change at this point
data transferred
(n bytes + acknowledge)
SC16IS740_750_760_6 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 06 — 13 May 2008 41 of 62
NXP Semiconductors SC16IS740/750/760
Single UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
10.3 Addressing
Before any data is transmitted or received, the master must send the address of the
receiver via the SDA line. The first byte after the START condition carries the address of
the slave device and the read/write bit. Table 32 shows how the SC16IS740/750/760’s
address can be selected by using A1 and A0 pins. For example, if these 2 pins are
connected to VDD, then the SC16IS740/750/760’s address is set to 0x90, and the master
communicates with it through this address.
[1] X = logic 0 for write cycle; X = logic 1 for read cycle.
10.4 Use of subaddresses
When a master communicates with the SC16IS740/750/760 it must send a subaddress in
the byte following the slave address byte. This subaddress is the internal address of the
word the master wants to access for a single byte transfer, or the beginning of a sequence
of locations for a multi-byte transfer. A subaddress is an 8-bit byte. Unlike the device
address, it does not contain a direction (R/W) bit, and like any byte transferred on the bus
it must be followed by an acknowledge.
Table 33 shows the breakdown of the subaddress (register address) byte. Bit 0 is not
used, bits [2:1] are both set to zeroes, bits [6:3] are used to select one of the device’s
internal registers, and bit 7 is not used.
A register write cycle is shown in Figure 22. The START is followed by a slave address
byte with the direction bit set to ‘write’, a subaddress byte, a number of data bytes, and a
STOP signal. The subaddress indicates which register the master wants to access, and
the data bytes which follow will be written one after the other to the subaddress location.
Table 32. SC16IS740/750/760 address map
A1 A0 SC16IS750/760 I2C addresses (hex)[1]
VDD VDD 0x90 (1001 000X)
VDD VSS 0x92 (1001 001X)
VDD SCL 0x94 (1001 010X)
VDD SDA 0x96 (1001 011X)
VSS VDD 0x98 (1001 100X)
VSS VSS 0x9A (1001 101X)
VSS SCL 0x9C (1001 110X)
VSS SDA 0x9E (1001 111X)
SCL VDD 0xA0 (1010 000X)
SCL VSS 0xA2 (1010 001X)
SCL SCL 0xA4 (1010 010X)
SCL SDA 0xA6 (1010 011X)
SDA VDD 0xA8 (1010 100X)
SDA VSS 0xAA (1010 101X)
SDA SCL 0xAC (1010 110X)
SDA SDA 0xAE (1010 111X)
SC16IS740_750_760_6 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 06 — 13 May 2008 42 of 62
NXP Semiconductors SC16IS740/750/760
Single UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
Table 33 and Table 34 show the bits’ presentation at the subaddress byte for I2C-bus and
SPI interfaces. Bit 0 is not used, bits 2:1 select the channel, bits 6:3 select one of the
UART internal registers. Bit 7 is not used with the I2C-bus interface, but it is used by the
SPI interface to indicate a read or a write operation.
The register read cycle (see Figure 23) commences in a similar manner, with the master
sending a slave address with the direction bit set to ‘write’ with a following subaddress.
Then, in order to reverse the direction of the transfer, the master issues a repeated START
followed again by the device address, but this time with the direction bit set to ‘read’. The
data bytes starting at the internal subaddress will be clocked out of the device, each
followed by a master-generated acknowledge. The last byte of the read cycle will be
followed by a negative acknowledge, signalling the end of transfer. The cycle is terminated
by a STOP signal.
White block: host to SC16IS740/750/760
Grey block: SC16IS740/750/760 to host
(1) See Table 33 for additional information.
Fig 22. Master writes to slave
S SLAVE ADDRESS
002aab047
W A REGISTER ADDRESS(1) AnDATA A P
White block: host to SC16IS740/750/760
Grey block: SC16IS740/750/760 to host
(1) See Table 33 for additional information.
Fig 23. Master read from slave
S SLAVE ADDRESS
002aab048
W A REGISTER ADDRESS(1) A
NA P
S SLAVE ADDRESS R A
nDATA A LAST DATA
Table 33. Register address byte (I2C)
Bit Name Function
7 - not used
6:3 A[3:0] UART’s internal register select
2:1 CH1, CH0 channel select: CH1 = 0, CH0 = 0
Other values are reserved and should not be used.
0 - not used
xxxx xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx x xxxxxxxxxxxxxx xxxxxxxxxx xxx xxxxxx xxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxxx
xxxxx xxxxxx xx xxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxx xxxxxxx xxxxxxxxxxxxxxxxxxx
xxxxxxxxxxxxxxxx xxxxxxxxxxxxxx xxxxxx xx xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxxxxx xxxxxxx
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxx xxxxx x x
SC16IS740_750_760_6 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 06 — 13 May 2008 43 of 62
NXP Semiconductors SC16IS740/750/760
Single UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
11. SPI operation
R/W = 0; A[3:0] = register address; CH1 = 0, CH0 = 0
a. Register write
R/W = 1; A[3:0] = register address; CH1 = 0, CH0 = 0
b. Register read
R/W = 0; A[3:0] = 0000; CH1 = 0, CH0 = 0
c. FIFO write cycle
R/W = 1; A[3:0] = 0000; CH1 = 0, CH0 = 0
d. FIFO read cycle
(1) Last bit (D0) of the last byte to be written to the transmit FIFO.
(2) Last bit (D0) of the last byte to be read from the receive FIFO.
Fig 24. SPI operation
SI A1A2A3
R/W
SCLK
CH1A0 XCH0 D6D7 D4D5 D2D3 D0D1
002aab433
SI A1A2A3
R/W
SCLK
CH1A0 XCH0
002aab434
SO D6D7 D4D5 D2D3 D0D1
SI A1A2A3
R/W
SCLK
CH1A0 XCH0 D6D7 D4D5 D2D3 D0D1
002aab435
D6D7 D4D5 D2D3 D0D1
last bit(1)
SI A1A2A3
R/W
SCLK
CH1A0 XCH0
002aab436
SO D6D7 D4D5 D2D3 D0D1 D0D1
last bit(2)
D6D7 D4D5 D2D3
SC16IS740_750_760_6 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 06 — 13 May 2008 44 of 62
NXP Semiconductors SC16IS740/750/760
Single UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
12. Limiting values
[1] 5.5 V steady state voltage tolerance on inputs and outputs is valid only when the supply voltage is present.
4.6 V steady state voltage tolerance on inputs and outputs when no supply voltage is present.
Table 34. Register address byte (SPI)
Bit Name Function
7R/
W 1: read from UART
0: write to UART
6:3 A[3:0] UART’s internal register select
2:1 CH1, CH0 channel select: CH1 = 0, CH0 = 0
Other values are reserved and should not be used.
0 - not used
Table 35. Limiting values
In accordance with the Absolute Maximum Rating System (IEC 60134).
Symbol Parameter Conditions Min Max Unit
VDD supply voltage 0.3 +4.6 V
VIinput voltage any input 0.3 +5.5[1] V
IIinput current any input 10 +10 mA
IOoutput current any output 10 +10 mA
Ptot total power dissipation - 300 mW
P/out power dissipation per
output -50mW
Tamb ambient temperature operating
VDD = 2.5 V ±0.2 V 40 +85 °C
VDD = 3.3 V ±0.3 V 40 +95 °C
Tjjunction temperature - +125 °C
Tstg storage temperature 65 +150 °C
SC16IS740_750_760_6 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 06 — 13 May 2008 45 of 62
NXP Semiconductors SC16IS740/750/760
Single UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
13. Static characteristics
Table 36. Static characteristics
V
DD
= 2.5 V
±
0.2 V, T
amb
=
40
°
Cto+85
°
C; or V
DD
= 3.3 V
±
0.3 V, T
amb
=
40
°
Cto+95
°
C; unless otherwise specified.
Symbol Parameter Conditions VDD = 2.5 V VDD = 3.3 V Unit
Min Max Min Max
Supplies
VDD supply voltage 2.3 2.7 3.0 3.6 V
IDD supply current operating; no load - 6.0 - 6.0 mA
Inputs I2C/SPI, RX, CTS
VIH HIGH-level input voltage 1.6 5.5[1] 2.0 5.5[1] V
VIL LOW-level input voltage - 0.6 - 0.8 V
ILleakage current input; VI= 0 V or 5.5 V[1] -1-1µA
Ciinput capacitance -3-3pF
Outputs TX, RTS, SO
VOH HIGH-level output voltage IOH =400 µA 1.85 - - - V
IOH =4 mA - - 2.4 - V
VOL LOW-level output voltage IOL = 1.6 mA - 0.4 - - V
IOL = 4 mA - - - 0.4 V
Cooutput capacitance -4-4pF
Inputs/outputs GPIO0 to GPIO7 (SC16IS750 and SC16IS760 only)
VIH HIGH-level input voltage 1.6 5.5[1] 2.0 5.5[1] V
VIL LOW-level input voltage - 0.6 - 0.8 V
VOH HIGH-level output voltage IOH =400 µA 1.85 - - - V
IOH =4 mA - - 2.4 - V
VOL LOW-level output voltage IOL = 1.6 mA - 0.4 - - V
IOL = 4 mA - - - 0.4 V
ILleakage current input; VI= 0 V or 5.5 V[1] -1-1µA
Cooutput capacitance -4-4pF
Output IRQ
VOL LOW-level output voltage IOL = 1.6 mA - 0.4 - - V
IOL = 4 mA - - - 0.4 V
Cooutput capacitance -4-4pF
I2C-bus input/output SDA
VIH HIGH-level input voltage 1.6 5.5[1] 2.0 5.5[1] V
VIL LOW-level input voltage - 0.6 - 0.8 V
VOL LOW-level output voltage IOL = 1.6 mA - 0.4 - - V
IOL = 4 mA - - - 0.4 V
ILleakage current input; VI= 0 V or 5.5 V[1] -10-10µA
Cooutput capacitance -7-7pF
SC16IS740_750_760_6 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 06 — 13 May 2008 46 of 62
NXP Semiconductors SC16IS740/750/760
Single UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
[1] 5.5 V steady state voltage tolerance on inputs and outputs is valid only when the supply voltage is present. 3.8 V steady state voltage
tolerance on inputs and outputs when no supply voltage is present.
[2] XTAL2 should be left open when XTAL1 is driven by an external clock.
I2C-bus inputs SCL, CS/A0, SI/A1
VIH HIGH-level input voltage 1.6 5.5[1] 2.0 5.5[1] V
VIL LOW-level input voltage - 0.6 - 0.8 V
ILleakage current input; VI= 0 V or 5.5 V[1] -10-10µA
Ciinput capacitance -7-7pF
Clock input XTAL1[2]
VIH HIGH-level input voltage 1.8 5.5[1] 2.4 5.5[1] V
VIL LOW-level input voltage - 0.45 - 0.6 V
ILleakage current input; VI= 0 V or 5.5 V[1] 30 +30 30 +30 µA
Ciinput capacitance -3-3pF
Sleep current
IDD(sleep) sleep mode supply current inputs are at VDD or ground - 30 - 30 µA
Table 36. Static characteristics
…continued
V
DD
= 2.5 V
±
0.2 V, T
amb
=
40
°
Cto+85
°
C; or V
DD
= 3.3 V
±
0.3 V, T
amb
=
40
°
Cto+95
°
C; unless otherwise specified.
Symbol Parameter Conditions VDD = 2.5 V VDD = 3.3 V Unit
Min Max Min Max
SC16IS740_750_760_6 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 06 — 13 May 2008 47 of 62
NXP Semiconductors SC16IS740/750/760
Single UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
14. Dynamic characteristics
[1] A detailed description of the I2C-bus specification, with applications, is given in user manual UM10204:
“I2C-bus specification and user
manual”
. This may be found at www.nxp.com/acrobat_download/usermanuals/UM10204_3.pdf.
[2] Minimum SCL clock frequency is limited by the bus time-out feature, which resets the serial bus interface if SDA is held LOW for a
minimum of 25 ms.
[3] Only applicable to the SC16IS750 and SC16IS760.
[4] 2 XTAL1 clocks or 3 µs, whichever is less.
Table 37. I2C-bus timing specifications[1]
All the timing limits are valid within the operating supply voltage, ambient temperature range and output load;
V
DD
= 2.5 V
±
0.2 V, T
amb
=
40
°
Cto+85
°
C; or V
DD
= 3.3 V
±
0.3 V, T
amb
=
40
°
Cto+95
°
C; and refer to V
IL
and V
IH
with
an input voltage of V
SS
to V
DD
. All output load = 25 pF, except SDA output load = 400 pF.
Symbol Parameter Conditions Standard mode
I2C-bus Fast mode
I2C-bus Unit
Min Max Min Max
fSCL SCL clock frequency [2] 0 100 0 400 kHz
tBUF bus free time between a STOP and START
condition 4.7 - 1.3 - µs
tHD;STA hold time (repeated) START condition 4.0 - 0.6 - µs
tSU;STA set-up time for a repeated START
condition 4.7 - 0.6 - µs
tSU;STO set-up time for STOP condition 4.7 - 0.6 - µs
tHD;DAT data hold time 0 - 0 - ns
tVD;ACK data valid acknowledge time - 0.6 - 0.6 µs
tVD;DAT data valid time SCL LOW to
data out valid - 0.6 - 0.6 ns
tSU;DAT data set-up time 250 - 150 - ns
tLOW LOW period of the SCL clock 4.7 - 1.3 - µs
tHIGH HIGH period of the SCL clock 4.0 - 0.6 - µs
tffall time of both SDA and SCL signals - 300 - 300 ns
trrise time of both SDA and SCL signals - 1000 - 300 ns
tSP pulse width of spikes that must be
suppressed by the input filter - 50 - 50 ns
td1 I2C-bus GPIO output valid time [3] 0.5 - 0.5 - µs
td2 I2C-bus modem input interrupt valid time 0.2 - 0.2 - µs
td3 I2C-bus modem input interrupt clear time 0.2 - 0.2 - µs
td4 I2C input pin interrupt valid time 0.2 - 0.2 - µs
td5 I2C input pin interrupt clear time 0.2 - 0.2 - µs
td6 I2C-bus receive interrupt valid time 0.2 - 0.2 - µs
td7 I2C-bus receive interrupt clear time 0.2 - 0.2 - µs
td8 I2C-bus transmit interrupt clear time 1.0 - 0.5 - µs
td15 SCL delay time after reset [4] 3-3-µs
tw(rst) reset pulse width 3 - 3 - µs
SC16IS740_750_760_6 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 06 — 13 May 2008 48 of 62
NXP Semiconductors SC16IS740/750/760
Single UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
Fig 25. SCL delay after reset
002aab437
RESET
SCL
td15
tw(rst)
Rise and fall times refer to VIL and VIH.
Fig 26. I2C-bus timing diagram
SCL
SDA
tHD;STA tSU;DAT tHD;DAT
tf
tBUF
tSU;STA tLOW tHIGH
tVD;ACK
002aab489
tSU;STO
protocol START
condition
(S)
bit 7
MSB
(A7)
bit 6
(A6)
bit 0
LSB
(R/W)
acknowledge
(A)
STOP
condition
(P)
1/fSCL
tr
tVD;DAT
tSP
Fig 27. Write to output (SC16IS750 and SC16IS760 only)
002aab255
AW
SDA A
GPIOn
DATA A
IOSTATE REG.
SLAVE ADDRESS A
td1
Fig 28. Modem input pin interrupt (SC16IS750 and SC16IS760 only)
002aab256
AW
SDA A R
IRQ
td2
S A DATA A
ACK to master
SLAVE ADDRESSMSR REGISTER
SLAVE ADDRESS A
td3
MODEM pin
SC16IS740_750_760_6 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 06 — 13 May 2008 49 of 62
NXP Semiconductors SC16IS740/750/760
Single UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
Fig 29. GPIO pin interrupt (SC16IS750 and SC16IS760 only)
002aab257
AW
SDA A R
IRQ
td4
S A DATA A
ACK from master
SLAVE ADDRESSIOSTATE REG.
SLAVE ADDRESS A
td5
GPIOn
P
ACK from slaveACK from slave
Fig 30. Receive interrupt
D0 D1 D2 D3 D4 D5 D6 D7
002aab258
next
start
bit
stop
bit
start
bit
td6
RX
IRQ
Fig 31. Receive interrupt clear
002aab259
AW
SDA A R
IRQ
S A DATA A
SLAVE ADDRESSRHR
SLAVE ADDRESS A
td7
P
Fig 32. Transmit interrupt clear
002aab260
AW
SDA
IRQ
ADATA A
THR REGISTER
SLAVE ADDRESS A
td8
SC16IS740_750_760_6 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 06 — 13 May 2008 50 of 62
NXP Semiconductors SC16IS740/750/760
Single UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
[1] Applies to external clock, crystal oscillator max. 24 MHz.
[2]
Table 38. fXTAL dynamic characteristics
V
DD
= 2.5 V
±
0.2 V, T
amb
=
40
°
Cto+85
°
C; or V
DD
= 3.3 V
±
0.3 V, T
amb
=
40
°
Cto+95
°
C
Symbol Parameter Conditions VDD = 2.5 V VDD = 3.3 V Unit
Min Max Min Max
tw1 clock pulse duration 10 - 6 - ns
tw2 clock pulse duration 10 - 6 - ns
fXTAL frequency on pin XTAL [1][2] - 48 - 80 MHz
f
XTAL 1
tw3
-------
=
Fig 33. External clock timing
EXTERNAL
CLOCK
002aaa112
tw3
tw2 tw1
Table 39. SC16IS740/750 SPI-bus timing specifications
All the timing limits are valid within the operating supply voltage, ambient temperature range and output load;
V
DD
= 2.5 V
±
0.2 V, T
amb
=
40
°
Cto+85
°
C; or V
DD
= 3.3 V
±
0.3 V, T
amb
=
40
°
Cto+95
°
C; and refer to V
IL
and V
IH
with
an input voltage of V
SS
to V
DD
. All output load = 25 pF, unless otherwise specified.
Symbol Parameter Conditions Min Typ Max Unit
tTR CS HIGH to SO 3-state delay time CL= 100 pF - - 100 ns
tCSS CS to SCLK setup time 100 - - ns
tCSH CS to SCLK hold time 20 - - ns
tDO SCLK fall to SO valid delay time CL= 100 pF - - 100 ns
tDS SI to SCLK setup time 100 - - ns
tDH SI to SCLK hold time 20 - - ns
tCP SCLK period tCL + tCH 250 - - ns
tCH SCLK HIGH time 100 - - ns
tCL SCLK LOW time 100 - - ns
tCSW CS HIGH pulse width 200 - - ns
td9 SPI output data valid time 200 - - ns
td10 SPI modem output data valid time 200 - - ns
td11 SPI transmit interrupt clear time 200 - - ns
td12 SPI modem input interrupt clear time 200 - - ns
td13 SPI interrupt clear time 200 - - ns
td14 SPI receive interrupt clear time 200 - - ns
tw(rst) reset pulse width 3 - - µs
SC16IS740_750_760_6 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 06 — 13 May 2008 51 of 62
NXP Semiconductors SC16IS740/750/760
Single UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
Table 40. SC16IS760 SPI-bus timing specifications
All the timing limits are valid within the operating supply voltage, ambient temperature range and output load;
V
DD
= 2.5 V
±
0.2 V, T
amb
=
40
°
Cto+85
°
C; or V
DD
= 3.3 V
±
0.3 V, T
amb
=
40
°
Cto+95
°
C and refer to V
IL
and V
IH
with
an input voltage of V
SS
to V
DD
. All output load = 25 pF, unless otherwise specified.
Symbol Parameter Conditions VDD = 2.5 V VDD = 3.3 V Unit
Min Max Min Max
tTR CS HIGH to SO 3-state delay time CL= 100 pF - 100 - 100 ns
tCSS CS to SCLK setup time 100 - 100 - ns
tCSH CS to SCLK hold time 5 - 5 - ns
tDO SCLK fall to SO valid delay time CL= 100 pF - 25 - 20 ns
tDS SI to SCLK setup time 10 - 10 - ns
tDH SI to SCLK hold time 10 - 10 - ns
tCP SCLK period tCL + tCH 83 - 67 - ns
tCH SCLK HIGH time 30 - 25 - ns
tCL SCLK LOW time 30 - 25 - ns
tCSW CS HIGH pulse width 200 - 200 - ns
td9 SPI output data valid time 200 - 200 - ns
td10 SPI modem output data valid time 200 - 200 - ns
td11 SPI transmit interrupt clear time 200 - 200 - ns
td12 SPI modem input interrupt clear time 200 - 200 - ns
td13 SPI interrupt clear time 200 - 200 - ns
td14 SPI receive interrupt clear time 200 - 200 - ns
tw(rst) reset pulse width 3 - 3 - µs
Fig 34. Detailed SPI-bus timing
tCSH tCSS tCL tCH tCSH
tDO tTR
tDS
tDH
SO
SI
SCLK
CS
002aab066
tCSW
SC16IS740_750_760_6 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 06 — 13 May 2008 52 of 62
NXP Semiconductors SC16IS740/750/760
Single UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
R/W = 0; A[3:0] = IOState (0x0B); CH1 = 0; CH0 = 0
Fig 35. SPI write IOState to GPIO switch (SC16IS750 and SC16IS760 only)
SI A1A2A3
R/W
SCLK
CH1A0 XCH0
002aab438
GPIOx
D6D7 D4D5 D2D3 D0D1
CS
td9
R/W = 0; A[3:0] = MCR (0x04); CH1 = 0; CH0 = 0
Fig 36. SPI write MCR to DTR output switch (SC16IS750 and SC16IS760 only)
SI A1A2A3
R/W
SCLK
CH1A0 XCH0
002aab439
DTR (GPIO5)
D6D7 D4D5 D2D3 D0D1
CS
td10
R/W = 0; A[3:0] = THR (0x00); CH1 = 0; CH0 = 0
Fig 37. SPI write THR to clear TX INT
SI A1A2A3
R/W
SCLK
CH1A0 XCH0
002aab440
SO
D6D7 D4D5 D2D3 D0D1
CS
td11
IRQ
SC16IS740_750_760_6 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 06 — 13 May 2008 53 of 62
NXP Semiconductors SC16IS740/750/760
Single UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
R/W = 1; A[3:0] = MSR (0x06); CH1 = 0; CH0 = 0
Fig 38. Read MSR to clear modem INT (SC16IS750 and SC16IS760 only)
SI A1A2A3
R/W
SCLK
CH1A0 XCH0
002aab441
SO
CS
td12
IRQ
D6D7 D4D5 D2D3 D0D1
R/W = 1; A[3:0] = IOState (0x0B); CH1 = 0; CH0 = 0
Fig 39. Read IOState to clear GPIO INT (SC16IS750 and SC16IS760 only)
SI A1A2A3
R/W
SCLK
CH1A0 XCH0
002aab442
SO
CS
td13
IRQ
D6D7 D4D5 D2D3 D0D1
R/W = 1; A[3:0] = RHR (0x00); CH1 = 0; CH0 = 0
Fig 40. Read RHR to clear RX INT
SI A1A2A3
R/W
SCLK
CH1A0 XCH0
002aab443
SO
CS
td14
IRQ
D6D7 D4D5 D2D3 D0D1
SC16IS740_750_760_6 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 06 — 13 May 2008 54 of 62
NXP Semiconductors SC16IS740/750/760
Single UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
15. Package outline
Fig 41. Package outline SOT403-1 (TSSOP16)
UNIT A1A2A3bpcD
(1) E(2) (1)
eH
ELL
pQZywv θ
REFERENCES
OUTLINE
VERSION EUROPEAN
PROJECTION ISSUE DATE
IEC JEDEC JEITA
mm 0.15
0.05 0.95
0.80 0.30
0.19 0.2
0.1 5.1
4.9 4.5
4.3 0.65 6.6
6.2 0.4
0.3 0.40
0.06 8
0
o
o
0.13 0.10.21
DIMENSIONS (mm are the original dimensions)
Notes
1. Plastic or metal protrusions of 0.15 mm maximum per side are not included.
2. Plastic interlead protrusions of 0.25 mm maximum per side are not included.
0.75
0.50
SOT403-1 MO-153 99-12-27
03-02-18
wM
bp
D
Z
e
0.25
18
16 9
θ
A
A1
A2
Lp
Q
detail X
L
(A )
3
HE
E
c
vMA
X
A
y
0 2.5 5 mm
scale
TSSOP16: plastic thin shrink small outline package; 16 leads; body width 4.4 mm SOT403-1
A
max.
1.1
pin 1 index
SC16IS740_750_760_6 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 06 — 13 May 2008 55 of 62
NXP Semiconductors SC16IS740/750/760
Single UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
Fig 42. Package outline SOT616-3 (HVQFN24)
0.51 0.2
A1Eh
b
UNIT ye
REFERENCES
OUTLINE
VERSION EUROPEAN
PROJECTION ISSUE DATE
IEC JEDEC JEITA
mm 4.1
3.9
Dh
2.75
2.45
y1
4.1
3.9 2.75
2.45
e1
2.5
e2
2.5
0.30
0.18
c
0.05
0.00 0.05 0.1
DIMENSIONS (mm are the original dimensions)
SOT616-3 MO-220 04-11-19
05-03-10
- - -- - -
0.5
0.3
L
0.1
v
0.05
w
0 2.5 5 mm
scale
SOT616-3
HVQFN24: plastic thermal enhanced very thin quad flat package; no leads;
24 terminals; body 4 x 4 x 0.85 mm
A(1)
max.
AA1c
detail X
y
y1C
e
L
Eh
Dh
e
e1
b
712
24 19
18
13
6
1
X
D
E
C
BA
e2
terminal 1
index area
terminal 1
index area
AC
CB
vM
wM
1/2 e
1/2 e
E(1)
Note
1. Plastic or metal protrusions of 0.075 mm maximum per side are not included.
D(1)
SC16IS740_750_760_6 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 06 — 13 May 2008 56 of 62
NXP Semiconductors SC16IS740/750/760
Single UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
Fig 43. Package outline SOT355-1 (TSSOP24)
UNIT A1A2A3bpcD
(1) E(2) (1)
eH
ELL
pQZywv θ
REFERENCES
OUTLINE
VERSION EUROPEAN
PROJECTION ISSUE DATE
IEC JEDEC JEITA
mm 0.15
0.05 0.95
0.80 0.30
0.19 0.2
0.1 7.9
7.7 4.5
4.3 0.65 6.6
6.2 0.4
0.3 8
0
o
o
0.13 0.10.21
DIMENSIONS (mm are the original dimensions)
Notes
1. Plastic or metal protrusions of 0.15 mm maximum per side are not included.
2. Plastic interlead protrusions of 0.25 mm maximum per side are not included.
0.75
0.50
SOT355-1 MO-153 99-12-27
03-02-19
0.25 0.5
0.2
wM
bp
Z
e
112
24 13
pin 1 index
θ
A
A1
A2
Lp
Q
detail X
L
(A )
3
HE
E
c
vMA
X
A
D
y
0 2.5 5 mm
scale
TSSOP24: plastic thin shrink small outline package; 24 leads; body width 4.4 mm SOT355-1
A
max.
1.1
SC16IS740_750_760_6 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 06 — 13 May 2008 57 of 62
NXP Semiconductors SC16IS740/750/760
Single UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
16. Handling information
Inputs and outputs are protected against electrostatic discharge in normal handling.
However, to be completely safe you must take normal precautions appropriate to handling
integrated circuits.
17. Soldering of SMD packages
This text provides a very brief insight into a complex technology. A more in-depth account
of soldering ICs can be found in Application Note
AN10365 “Surface mount reflow
soldering description”
.
17.1 Introduction to soldering
Soldering is one of the most common methods through which packages are attached to
Printed Circuit Boards (PCBs), to form electrical circuits. The soldered joint provides both
the mechanical and the electrical connection. There is no single soldering method that is
ideal for all IC packages. Wave soldering is often preferred when through-hole and
Surface Mount Devices (SMDs) are mixed on one printed wiring board; however, it is not
suitable for fine pitch SMDs. Reflow soldering is ideal for the small pitches and high
densities that come with increased miniaturization.
17.2 Wave and reflow soldering
Wave soldering is a joining technology in which the joints are made by solder coming from
a standing wave of liquid solder. The wave soldering process is suitable for the following:
Through-hole components
Leaded or leadless SMDs, which are glued to the surface of the printed circuit board
Not all SMDs can be wave soldered. Packages with solder balls, and some leadless
packages which have solder lands underneath the body, cannot be wave soldered. Also,
leaded SMDs with leads having a pitch smaller than ~0.6 mm cannot be wave soldered,
due to an increased probability of bridging.
The reflow soldering process involves applying solder paste to a board, followed by
component placement and exposure to a temperature profile. Leaded packages,
packages with solder balls, and leadless packages are all reflow solderable.
Key characteristics in both wave and reflow soldering are:
Board specifications, including the board finish, solder masks and vias
Package footprints, including solder thieves and orientation
The moisture sensitivity level of the packages
Package placement
Inspection and repair
Lead-free soldering versus SnPb soldering
17.3 Wave soldering
Key characteristics in wave soldering are:
SC16IS740_750_760_6 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 06 — 13 May 2008 58 of 62
NXP Semiconductors SC16IS740/750/760
Single UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
Process issues, such as application of adhesive and flux, clinching of leads, board
transport, the solder wave parameters, and the time during which components are
exposed to the wave
Solder bath specifications, including temperature and impurities
17.4 Reflow soldering
Key characteristics in reflow soldering are:
Lead-free versus SnPb soldering; note that a lead-free reflow process usually leads to
higher minimum peak temperatures (see Figure 44) than a SnPb process, thus
reducing the process window
Solder paste printing issues including smearing, release, and adjusting the process
window for a mix of large and small components on one board
Reflow temperature profile; this profile includes preheat, reflow (in which the board is
heated to the peak temperature) and cooling down. It is imperative that the peak
temperature is high enough for the solder to make reliable solder joints (a solder paste
characteristic). In addition, the peak temperature must be low enough that the
packages and/or boards are not damaged. The peak temperature of the package
depends on package thickness and volume and is classified in accordance with
Table 41 and 42
Moisture sensitivity precautions, as indicated on the packing, must be respected at all
times.
Studies have shown that small packages reach higher temperatures during reflow
soldering, see Figure 44.
Table 41. SnPb eutectic process (from J-STD-020C)
Package thickness (mm) Package reflow temperature (°C)
Volume (mm3)
< 350 350
< 2.5 235 220
2.5 220 220
Table 42. Lead-free process (from J-STD-020C)
Package thickness (mm) Package reflow temperature (°C)
Volume (mm3)
< 350 350 to 2000 > 2000
< 1.6 260 260 260
1.6 to 2.5 260 250 245
> 2.5 250 245 245
SC16IS740_750_760_6 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 06 — 13 May 2008 59 of 62
NXP Semiconductors SC16IS740/750/760
Single UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
For further information on temperature profiles, refer to Application Note
AN10365
“Surface mount reflow soldering description”
.
18. Abbreviations
MSL: Moisture Sensitivity Level
Fig 44. Temperature profiles for large and small components
001aac844
temperature
time
minimum peak temperature
= minimum soldering temperature
maximum peak temperature
= MSL limit, damage level
peak
temperature
Table 43. Abbreviations
Acronym Description
CPU Central Processing Unit
FIFO First In, First Out
GPIO General Purpose Input/Output
I2C-bus Inter IC bus
IrDA Infrared Data Association
LCD Liquid Crystal Display
MIR Medium InfraRed
POR Power-On Reset
SIR Serial InfraRed
SPI Serial Peripheral Interface
UART Universal Asynchronous Receiver/Transmitter
SC16IS740_750_760_6 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 06 — 13 May 2008 60 of 62
NXP Semiconductors SC16IS740/750/760
Single UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
19. Revision history
Table 44. Revision history
Document ID Release date Data sheet status Change notice Supersedes
SC16IS740_750_760_6 20080513 Product data sheet - SC16IS740_750_760_5
Modifications: Figure 24 “SPI operation” updated; added Figure note [1] and Figure note [2]
Table 37 “I2C-bus timing specifications[1]:
added specification tw(rst)
updated Table note [1]
Table note [4]: changed from “X1” to “XTAL1”
Figure 25 “SCL delay after reset” updated; added timing tw(rst)
Table 39 “SC16IS740/750 SPI-bus timing specifications” updated; added specification tw(rst)
Figure 34 “Detailed SPI-bus timing” updated; adjusted timing tCSH
Table 40 “SC16IS760 SPI-bus timing specifications”:
added specification tw(rst)
tCSH(min) changed from “20 ns” to “5 ns” (for both 2.5 V and 3.3 V VDD voltages)
updated SMD package soldering information
SC16IS740_750_760_5 20061116 Product data sheet - SC16IS740_750_760_4
SC16IS740_750_760_4 20061030 Product data sheet - SC16IS740_750_760_3
SC16IS740_750_760_3 20060522 Product data sheet - SC16IS740_750_760_2
SC16IS740_750_760_2 20060330 Product data sheet - SC16IS740_750_760_1
SC16IS740_750_760_1
(9397 750 14832) 20060104 Product data sheet - -
SC16IS740_750_760_6 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 06 — 13 May 2008 61 of 62
NXP Semiconductors SC16IS740/750/760
Single UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
20. Legal information
20.1 Data sheet status
[1] Please consult the most recently issued document before initiating or completing a design.
[2] The term ‘short data sheet’ is explained in section “Definitions”.
[3] The product status of device(s) described in this document may have changed since this document was published and may differ in case of multiple devices. The latest product status
information is available on the Internet at URL http://www.nxp.com.
20.2 Definitions
Draft — The document is a draft version only. The content is still under
internal review and subject to formal approval, which may result in
modifications or additions. NXP Semiconductors does not give any
representations or warranties as to the accuracy or completeness of
information included herein and shall have no liability for the consequences of
use of such information.
Short data sheet — A short data sheet is an extract from a full data sheet
with the same product type number(s) and title. A short data sheet is intended
for quick reference only and should not be relied upon to contain detailed and
full information. For detailed and full information see the relevant full data
sheet, which is available on request via the local NXP Semiconductors sales
office. In case of any inconsistency or conflict with the short data sheet, the
full data sheet shall prevail.
20.3 Disclaimers
General — Information in this document is believed to be accurate and
reliable. However, NXP Semiconductors does not give any representations or
warranties, expressed or implied, as to the accuracy or completeness of such
information and shall have no liability for the consequences of use of such
information.
Right to make changes — NXP Semiconductors reserves the right to make
changes to information published in this document, including without
limitation specifications and product descriptions, at any time and without
notice. This document supersedes and replaces all information supplied prior
to the publication hereof.
Suitability for use — NXP Semiconductors products are not designed,
authorized or warranted to be suitable for use in medical, military, aircraft,
space or life support equipment, nor in applications where failure or
malfunction of an NXP Semiconductors product can reasonably be expected
to result in personal injury, death or severe property or environmental
damage. NXP Semiconductors accepts no liability for inclusion and/or use of
NXP Semiconductors products in such equipment or applications and
therefore such inclusion and/or use is at the customer’s own risk.
Applications — Applications that are described herein for any of these
products are for illustrative purposes only. NXP Semiconductors makes no
representation or warranty that such applications will be suitable for the
specified use without further testing or modification.
Limiting values — Stress above one or more limiting values (as defined in
the Absolute Maximum Ratings System of IEC 60134) may cause permanent
damage to the device. Limiting values are stress ratings only and operation of
the device at these or any other conditions above those given in the
Characteristics sections of this document is not implied. Exposure to limiting
values for extended periods may affect device reliability.
Terms and conditions of sale — NXP Semiconductors products are sold
subject to the general terms and conditions of commercial sale, as published
at http://www.nxp.com/profile/terms, including those pertaining to warranty,
intellectual property rights infringement and limitation of liability, unless
explicitly otherwise agreed to in writing by NXP Semiconductors. In case of
any inconsistency or conflict between information in this document and such
terms and conditions, the latter will prevail.
No offer to sell or license — Nothing in this document may be interpreted
or construed as an offer to sell products that is open for acceptance or the
grant, conveyance or implication of any license under any copyrights, patents
or other industrial or intellectual property rights.
20.4 Trademarks
Notice: All referenced brands, product names, service names and trademarks
are the property of their respective owners.
I2C-bus — logo is a trademark of NXP B.V.
21. Contact information
For more information, please visit: http://www.nxp.com
For sales office addresses, please send an email to: salesaddresses@nxp.com
Document status[1][2] Product status[3] Definition
Objective [short] data sheet Development This document contains data from the objective specification for product development.
Preliminary [short] data sheet Qualification This document contains data from the preliminary specification.
Product [short] data sheet Production This document contains the product specification.
NXP Semiconductors SC16IS740/750/760
Single UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
© NXP B.V. 2008. All rights reserved.
For more information, please visit: http://www.nxp.com
For sales office addresses, please send an email to: salesaddresses@nxp.com
Date of release: 13 May 2008
Document identifier: SC16IS740_750_760_6
Please be aware that important notices concerning this document and the product(s)
described herein, have been included in section ‘Legal information’.
22. Contents
1 General description. . . . . . . . . . . . . . . . . . . . . . 1
2 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
2.1 General features. . . . . . . . . . . . . . . . . . . . . . . . 1
2.2 I2C-bus features . . . . . . . . . . . . . . . . . . . . . . . . 2
2.3 SPI features . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
3 Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
4 Ordering information. . . . . . . . . . . . . . . . . . . . . 3
5 Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . 4
6 Pinning information. . . . . . . . . . . . . . . . . . . . . . 6
6.1 Pinning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
6.2 Pin description . . . . . . . . . . . . . . . . . . . . . . . . . 7
7 Functional description . . . . . . . . . . . . . . . . . . . 9
7.1 Trigger levels. . . . . . . . . . . . . . . . . . . . . . . . . . . 9
7.2 Hardware flow control. . . . . . . . . . . . . . . . . . . . 9
7.2.1 Auto RTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
7.2.2 Auto CTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
7.3 Software flow control . . . . . . . . . . . . . . . . . . . 11
7.3.1 RX. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
7.3.2 TX. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
7.4 Hardware reset, Power-On Reset (POR) and
software reset. . . . . . . . . . . . . . . . . . . . . . . . . 14
7.5 Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
7.5.1 Interrupt mode operation . . . . . . . . . . . . . . . . 16
7.5.2 Polled mode operation . . . . . . . . . . . . . . . . . . 16
7.6 Sleep mode. . . . . . . . . . . . . . . . . . . . . . . . . . . 17
7.7 Break and time-out conditions . . . . . . . . . . . . 17
7.8 Programmable baud rate generator . . . . . . . . 17
8 Register descriptions . . . . . . . . . . . . . . . . . . . 20
8.1 Receive Holding Register (RHR) . . . . . . . . . . 23
8.2 Transmit Holding Register (THR) . . . . . . . . . . 23
8.3 FIFO Control Register (FCR) . . . . . . . . . . . . . 23
8.4 Line Control Register (LCR) . . . . . . . . . . . . . . 24
8.5 Line Status Register (LSR). . . . . . . . . . . . . . . 26
8.6 Modem Control Register (MCR). . . . . . . . . . . 27
8.7 Modem Status Register (MSR). . . . . . . . . . . . 28
8.8 Interrupt Enable Register (IER) . . . . . . . . . . . 29
8.9 Interrupt Identification Register (IIR). . . . . . . . 30
8.10 Enhanced Features Register (EFR) . . . . . . . . 31
8.11 Division registers (DLL, DLH). . . . . . . . . . . . . 31
8.12 Transmission Control Register (TCR). . . . . . . 32
8.13 Trigger Level Register (TLR). . . . . . . . . . . . . . 32
8.14 Transmitter FIFO Level register (TXLVL) . . . . 32
8.15 Receiver FIFO Level register (RXLVL) . . . . . . 33
8.16 Programmable I/O pins Direction register
(IODir). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
8.17 Programmable I/O pins State Register
(IOState). . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
8.18 I/O Interrupt Enable Register (IOIntEna) . . . . 33
8.19 I/O Control register (IOControl) . . . . . . . . . . . 34
8.20 Extra Features Control Register (EFCR) . . . . 35
9 RS-485 features . . . . . . . . . . . . . . . . . . . . . . . . 35
9.1 Auto RS-485 RTS control. . . . . . . . . . . . . . . . 35
9.2 RS-485 RTS output inversion. . . . . . . . . . . . . 36
9.3 Auto RS-485. . . . . . . . . . . . . . . . . . . . . . . . . . 36
9.3.1 Normal multidrop mode . . . . . . . . . . . . . . . . . 36
9.3.2 Auto address detection. . . . . . . . . . . . . . . . . . 36
10 I2C-bus operation . . . . . . . . . . . . . . . . . . . . . . 37
10.1 Data transfers. . . . . . . . . . . . . . . . . . . . . . . . . 37
10.2 Addressing and transfer formats . . . . . . . . . . 38
10.3 Addressing. . . . . . . . . . . . . . . . . . . . . . . . . . . 41
10.4 Use of subaddresses . . . . . . . . . . . . . . . . . . . 41
11 SPI operation . . . . . . . . . . . . . . . . . . . . . . . . . . 43
12 Limiting values . . . . . . . . . . . . . . . . . . . . . . . . 44
13 Static characteristics . . . . . . . . . . . . . . . . . . . 45
14 Dynamic characteristics. . . . . . . . . . . . . . . . . 47
15 Package outline . . . . . . . . . . . . . . . . . . . . . . . . 54
16 Handling information . . . . . . . . . . . . . . . . . . . 57
17 Soldering of SMD packages. . . . . . . . . . . . . . 57
17.1 Introduction to soldering. . . . . . . . . . . . . . . . . 57
17.2 Wave and reflow soldering. . . . . . . . . . . . . . . 57
17.3 Wave soldering. . . . . . . . . . . . . . . . . . . . . . . . 57
17.4 Reflow soldering. . . . . . . . . . . . . . . . . . . . . . . 58
18 Abbreviations . . . . . . . . . . . . . . . . . . . . . . . . . 59
19 Revision history . . . . . . . . . . . . . . . . . . . . . . . 60
20 Legal information . . . . . . . . . . . . . . . . . . . . . . 61
20.1 Data sheet status. . . . . . . . . . . . . . . . . . . . . . 61
20.2 Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
20.3 Disclaimers. . . . . . . . . . . . . . . . . . . . . . . . . . . 61
20.4 Trademarks . . . . . . . . . . . . . . . . . . . . . . . . . . 61
21 Contact information . . . . . . . . . . . . . . . . . . . . 61
22 Contents. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62