SC16IS752; SC16IS762
Dual UART with I2C-bus/SPI interface, 64 bytes of transmit
and receive FIFOs, IrDA SIR built-in support
Rev. 9 — 22 March 2012
Product data sheet
1. General description
The SC16IS752/SC16IS762 is an I2C-bus/SPI bus interface to a dual-channel high
performance UART offering data rates up to 5 Mbit/s, low operating and sleeping current;
it also provides the application with 8 additional programmable I/O pins. The device
comes in very small HVQFN32 and TSSOP28 packages, which makes it ideally suitable
for hand-held, battery-operated applications. This chip enables seamless protocol
conversion from I2C-bus/SPI to RS-232/RS-485 and is fully bidirectional.
The SC16IS762 differs from the SC16IS752 in that it supports SPI clock speeds up to
15 Mbit/s instead of the 4 Mbit/s supported by the SC16IS752, and in that it supports IrDA
SIR up to 1.152 Mbit/s. In all other aspects, the SC16IS762 is functionally and electrically
the same as the SC16IS752.
The SC16IS752/SC16IS762’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 SC16IS752/SC16IS762 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 and benefits
2.1 General features
Dual full-duplex UART
I2C-bus or SPI interface selectable
3.3 V or 2.5 V operation
Industrial temperature range: 40 C to +95 C
64 bytes FIFO (transmitter and receiver)
Fully compatible with industrial standard 16C450 and equivalent
Baud rates up to 5 Mbit/s in 16 clock mode
Auto hardware flow control using RTS/CTS
Auto software flow control with programmable Xon/Xoff characters
Single or double Xon/Xoff characters
Automatic RS-485 support (automatic slave address detection)
Up to eight programmable I/O pins
RS-485 driver direction control via RTS signal
SC16IS752; SC16IS762
NXP Semiconductors
Dual UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
RS-485 driver direction control inversion
Built-in IrDA encoder and decoder supporting IrDA SIR with speeds up to 115.2 kbit/s
SC16IS762 supports IrDA SIR with speeds up to 1.152 Mbit/s1
Software reset
Transmitter and receiver can be enabled/disabled independent of each other
Receive and Transmit FIFO levels
Programmable special character detection
Fully programmable character formatting
5-bit, 6-bit, 7-bit or 8-bit character
Even, odd, or no parity
1, 11⁄2, or 2 stop bits
Line break generation and detection
Internal Loopback mode
Sleep current less than 30 A at 3.3 V
Industrial and commercial temperature ranges
5 V tolerant inputs
Available in HVQFN32 and TSSOP28 packages
2.2 I2C-bus features
Noise filter on SCL/SDA inputs
400 kbit/s (maximum)
Compliant with I2C-bus Fast mode
Slave mode only
2.3 SPI features
SC16IS752 supports 4 Mbit/s maximum SPI clock speed
SC16IS762 supports 15 Mbit/s maximum SPI clock speed
Slave mode only
SPI Mode 0
3. Applications
Factory automation and process control
Portable and battery operated devices
Cellular 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.
SC16IS752_SC16IS762
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 9 — 22 March 2012
© NXP B.V. 2012. All rights reserved.
2 of 60
SC16IS752; SC16IS762
NXP Semiconductors
Dual UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
4. Ordering information
Table 1.
Ordering information
Type number
SC16IS752IPW
Package
Name
Description
Version
TSSOP28
plastic thin shrink small outline package; 28 leads; body width 4.4 mm
SOT361-1
HVQFN32
plastic thermal enhanced very thin quad flat package; no leads; 32 terminals;
body 5 5 0.85 mm
SOT617-1
SC16IS762IPW
SC16IS752IBS
SC16IS762IBS
SC16IS752_SC16IS762
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 9 — 22 March 2012
© NXP B.V. 2012. All rights reserved.
3 of 60
SC16IS752; SC16IS762
NXP Semiconductors
Dual UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
5. Block diagram
VDD
VSS
SC16IS752/
SC16IS762
16C450
COMPATIBLE
REGISTER
SETS
SDA
SCL
A0
A1
VDD
TXA
RXA
RTSA
CTSA
TXB
RXB
RTSB
CTSB
I2C-BUS
1 kΩ (3.3 V)
1.5 kΩ (2.5 V)
IRQ
RESET
VDD
GPIO
REGISTER
I2C/SPI
GPIO7/RIA
GPIO6/CDA
GPIO5/DTRA
GPIO4/DSRA
GPIO3/RIB
GPIO2/CDB
GPIO1/DTRB
GPIO0/DSRB
002aab207
XTAL1
XTAL2
a. I2C-bus interface
VDD
VSS
SC16IS752/
SC16IS762
16C450
COMPATIBLE
REGISTER
SETS
SCLK
CS
SO
SI
VDD
TXA
RXA
RTSA
CTSA
TXB
RXB
RTSB
CTSB
SPI
1 kΩ (3.3 V)
1.5 kΩ (2.5 V)
IRQ
RESET
I2C/SPI
GPIO
REGISTER
GPIO7/RIA
GPIO6/CDA
GPIO5/DTRA
GPIO4/DSRA
GPIO3/RIB
GPIO2/CDB
GPIO1/DTRB
GPIO0/DSRB
002aab598
XTAL1
XTAL2
b. SPI interface
Fig 1.
SC16IS752_SC16IS762
Product data sheet
Block diagram of SC16IS752/SC16IS762
All information provided in this document is subject to legal disclaimers.
Rev. 9 — 22 March 2012
© NXP B.V. 2012. All rights reserved.
4 of 60
SC16IS752; SC16IS762
NXP Semiconductors
Dual UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
6. Pinning information
6.1 Pinning
RTSA
1
28 GPIO7/RIA
RTSA
1
28 GPIO7/RIA
CTSA
2
27 GPIO6/CDA
CTSA
2
27 GPIO6/CDA
TXA
3
26 GPIO5/DTRA
TXA
3
26 GPIO5/DTRA
RXA
4
25 GPIO4/DSRA
RXA
4
25 GPIO4/DSRA
RESET
5
24 RXB
RESET
5
24 RXB
XTAL1
6
23 TXB
XTAL1
6
23 TXB
XTAL2
7
22 VSS
XTAL2
7
VDD
8
21 GPIO3/RIB
VDD
8
I2C
9
20 GPIO2/CDB
SPI
9
A0 10
19 GPIO1/DTRB
CS 10
19 GPIO1/DTRB
A1 11
18 GPIO0/DSRB
SI 11
18 GPIO0/DSRB
SC16IS752IPW
SC16IS762IPW
n.c. 12
17 RTSB
SO 12
17 RTSB
SCL 13
16 CTSB
SCLK 13
16 CTSB
SDA 14
15 IRQ
VSS 14
15 IRQ
002aab599
a. I2C-bus interface
b. SPI interface
25 GPIO5/DTRA
26 GPIO6/CDA
27 GPIO7/RIA
28 VDD
29 VSS
30 RTSA
terminal 1
index area
31 CTSA
32 TXA
25 GPIO5/DTRA
26 GPIO6/CDA
27 GPIO7/RIA
28 VDD
29 VSS
30 RTSA
31 CTSA
32 TXA
Pin configuration for TSSOP28
terminal 1
index area
RXA
1
24 GPIO4/DSRA
RXA
1
24 GPIO4/DSRA
RESET
2
23 RXB
RESET
2
23 RXB
XTAL1
3
22 TXB
XTAL1
3
22 TXB
XTAL2
4
21 VSS
XTAL2
4
VDD
5
20 GPIO3/RIB
VDD
5
I2C
6
19 GPIO2/CDB
SPI
6
19 GPIO2/CDB
A0
7
18 GPIO1/DTRB
CS
7
18 GPIO1/DTRB
A1
8
17 GPIO0/DSRB
SI
8
17 GPIO0/DSRB
RTSB 16
20 GPIO3/RIB
CTSB 15
IRQ 14
VDD 13
VSS 12
VSS 11
9
SO
002aab658
21 VSS
SC16IS752IBS
SC16IS762IBS
SCLK 10
RTSB 16
CTSB 15
IRQ 14
VDD 13
VSS 12
SDA 11
9
n.c.
SCL 10
SC16IS752IBS
SC16IS762IBS
Transparent top view
002aab208
Transparent top view
a. I2C-bus interface
Fig 3.
21 GPIO3/RIB
20 GPIO2/CDB
002aab657
Fig 2.
22 VSS
SC16IS752IPW
SC16IS762IPW
b. SPI interface
Pin configuration for HVQFN32
SC16IS752_SC16IS762
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 9 — 22 March 2012
© NXP B.V. 2012. All rights reserved.
5 of 60
SC16IS752; SC16IS762
NXP Semiconductors
Dual UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
6.2 Pin description
Table 2.
Pin description
Symbol
CS/A0
Pin
Type Description
TSSOP28
HVQFN32
10
7
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.
To select the device address, please refer to Table 32.
CTSA
2
31
I
UART clear to send (active LOW), channel A. A logic 0 (LOW) on the
CTSA pin indicates the modem or data set is ready to accept transmit
data from the SC16IS752/SC16IS762. 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 Features Register
EFR[7] for hardware flow control operation.
CTSB
16
15
I
UART clear to send (active LOW), channel B. A logic 0 on the CTSB pin
indicates the modem or data set is ready to accept transmit data from the
SC16IS752/SC16IS762. 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 Features Register EFR[7] for
hardware flow control operation.
I2C/SPI
9
6
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.
IRQ
15
14
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 k for 2.5 V) must be connected between this pin and VDD.
SI/A1
11
8
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 the
A0 pin allows user to change the slave base address. To select the
device address, please refer to Table 32.
SO
12
9
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 the
I2C/SPI pin, this pin is undefined and must be left as not connected.
SCL/SCLK
13
10
I
I2C-bus or SPI input clock.
SDA
14
11
I/O
I2C-bus data input/output, open-drain if I2C-bus configuration is selected
by I2C/SPI pin. If SPI configuration is selected, this is not used and must
be connected to VSS.
GPIO0/DSRB
18
17
I/O
Programmable I/O pin or modem DSRB[1]
GPIO1/DTRB
19
18
I/O
Programmable I/O pin or modem DTRB[1]
GPIO2/CDB
20
19
I/O
Programmable I/O pin or modem CDB[1]
GPIO3/RIB
21
20
I/O
Programmable I/O pin or modem RIB[1]
GPIO4/DSRA
25
24
I/O
Programmable I/O pin or modem DSRA[2]
GPIO5/DTRA
26
25
I/O
Programmable I/O pin or modem DTRA[2]
GPIO6/CDA
27
26
I/O
Programmable I/O pin or modem CDA[2]
GPIO7/RIA
28
27
I/O
Programmable I/O pin or modem RIA[2]
SC16IS752_SC16IS762
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 9 — 22 March 2012
© NXP B.V. 2012. All rights reserved.
6 of 60
SC16IS752; SC16IS762
NXP Semiconductors
Dual UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
Table 2.
Pin description …continued
Symbol
Pin
Type Description
TSSOP28
HVQFN32
RESET
5
2
I
Hardware reset (active LOW)[3]
RTSA
1
30
O
UART request to send (active LOW), channel A. A logic 0 on the RTSA
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 Features Register (EFR[6]) for
hardware flow control operation.
RTSB
17
16
O
UART request to send (active LOW), channel B. A logic 0 on the RTSB
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 Features Register (EFR[6]) for
hardware flow control operation.
RXA
4
1
I
Channel A receiver input. During the local Loopback mode, the RXA
input pin is disabled and TXA data is connected to the UART RXA input
internally.
RXB
24
23
I
Channel B receiver input. During the local Loopback mode, the RXB
input pin is disabled and TXB data is connected to the UART RXB input
internally.
TXA
3
32
O
Channel A transmitter output. During the local Loopback mode, the TXA
output pin is disabled and TXA data is internally connected to the UART
RXA input.
TXB
23
22
O
Channel B transmitter output. During the local Loopback mode, the TXB
output pin is disabled and TXB data is internally connected to the UART
RXB input.
VDD
8
5, 13, 28
-
Power supply
VSS
22
12, 21,
29[4]
-
Ground
VSS
-
center
pad[4]
-
The center pad on the back side of the HVQFN32 package is metallic
and should be connected to ground on the printed-circuit board.
XTAL1
6
3
I
Crystal input or external clock input. A crystal can be connected between
XTAL1 and XTAL2 to form an internal oscillator circuit (see Figure 11).
Alternatively, an external clock can be connected to this pin.
XTAL2
7
4
O
Crystal output. (See also XTAL1.) XTAL2 is used as a crystal oscillator
output[5].
[1]
Selectable with IOControl register bit 2.
[2]
Selectable with IOControl register bit 1.
[3]
See Section 7.4 “Hardware Reset, Power-On Reset (POR) and Software Reset”.
[4]
HVQFN32 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.
[5]
XTAL2 should be left open when XTAL1 is driven by an external clock.
SC16IS752_SC16IS762
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 9 — 22 March 2012
© NXP B.V. 2012. All rights reserved.
7 of 60
SC16IS752; SC16IS762
NXP Semiconductors
Dual UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
7. Functional description
The UART will perform serial-to-I2C-bus conversion on data characters received from
peripheral devices or modems, and I2C-bus-to-serial conversion on data characters
transmitted by the host. The complete status of the SC16IS752/SC16IS762 UART can be
read at any time during functional operation by the host.
The SC16IS752/SC16IS762 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 SC16IS752/SC16IS762 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 SC16IS752/SC16IS762 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 FIFO Control Register
(FCR). The programmable trigger levels are available via the Trigger Level Register
(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 4). 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 Transmission Control Register (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.
SC16IS752_SC16IS762
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 9 — 22 March 2012
© NXP B.V. 2012. All rights reserved.
8 of 60
SC16IS752; SC16IS762
NXP Semiconductors
Dual UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
UART 1
UART 2
SERIAL TO
PARALLEL
RX
TX
PARALLEL
TO SERIAL
RX
FIFO
TX
FIFO
FLOW
CONTROL
RTS
PARALLEL
TO SERIAL
TX
CTS
RX
FLOW
CONTROL
SERIAL TO
PARALLEL
TX
FIFO
RX
FIFO
CTS
FLOW
CONTROL
RTS
FLOW
CONTROL
002aab656
Fig 4.
Auto flow control (Auto-RTS and Auto-CTS) example
7.2.1 Auto-RTS
Figure 5 shows RTS functional timing. The receiver FIFO trigger levels used in Auto-RTS
are stored in the TCR. 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 de-asserted. 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 de-assertion 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 re-assertion allows the sending
device to resume transmission.
RX
start
character
N
stop
start
character
N+1
stop
start
RTS
receive
FIFO
read
1
2
N
N+1
002aab040
(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 5.
RTS functional timing
SC16IS752_SC16IS762
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 9 — 22 March 2012
© NXP B.V. 2012. All rights reserved.
9 of 60
SC16IS752; SC16IS762
NXP Semiconductors
Dual UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
7.2.2 Auto-CTS
Figure 6 shows CTS functional timing. The transmitter circuitry checks CTS before
sending the next data character. When CTS is active, the transmitter sends the next
character. To stop the transmitter from sending the following character, CTS must be
de-asserted 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.
TX
start
bit 0 to bit 7
start
stop
bit 0 to bit 7
stop
CTS
002aab041
(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 6.
CTS functional timing
7.3 Software flow control
Software flow control is enabled through the Enhanced Features 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.
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
1
0
1
1
transmit Xon1, Xoff1
receiver compares Xon1 or Xon2, Xoff1 or Xoff2
0
1
1
1
transmit Xon2, Xoff2
receiver compares Xon1 or Xon2, Xoff1 or Xoff2
1
1
1
1
transmit Xon1 and Xon2, Xoff1 and Xoff2
0
0
1
1
no transmit flow control
receiver compares Xon1 and Xon2, Xoff1 and Xoff2
receiver compares Xon1 and Xon2, Xoff1 and Xoff2
SC16IS752_SC16IS762
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 9 — 22 March 2012
© NXP B.V. 2012. All rights reserved.
10 of 60
SC16IS752; SC16IS762
NXP Semiconductors
Dual 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 Interrupt Identification Register (IIR). The
special character is transferred to the RX FIFO.
7.3.1 Receive flow control
When software flow control operation is enabled, the SC16IS752/SC16IS762 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 Transmit flow control
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/Xon2 character is transmitted when the RX FIFO reaches the resume trigger level
programmed in TCR[7:4], or 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, 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 7 shows an example of software flow control.
SC16IS752_SC16IS762
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 9 — 22 March 2012
© NXP B.V. 2012. All rights reserved.
11 of 60
SC16IS752; SC16IS762
NXP Semiconductors
Dual UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
UART1
UART2
TRANSMIT FIFO
RECEIVE FIFO
data
PARALLEL-TO-SERIAL
SERIAL-TO-PARALLEL
Xoff–Xon–Xoff
SERIAL-TO-PARALLEL
PARALLEL-TO-SERIAL
Xon1 WORD
Xon1 WORD
Xon2 WORD
Xon2 WORD
Xoff1 WORD
Xoff1 WORD
Xoff2 WORD
Fig 7.
SC16IS752_SC16IS762
Product data sheet
compare
programmed
Xon-Xoff
characters
Xoff2 WORD
002aaa229
Example of software flow control
All information provided in this document is subject to legal disclaimers.
Rev. 9 — 22 March 2012
© NXP B.V. 2012. All rights reserved.
12 of 60
SC16IS752; SC16IS762
NXP Semiconductors
Dual 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 after reset.
Table 4.
Register reset
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 3:0 cleared; bits 7:4 input signals
Enhanced Features Register
all bits cleared
Receive Holding Register
pointer logic cleared
Transmit 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
all bits cleared
I/O interrupt enable
all bits cleared
I/O control
all bits cleared
Extra Features Control Register
all bits cleared
Remark: Registers DLL, DLH, SPR, XON1, XON2, XOFF1, XOFF2 are not reset by the
top-level reset signal RESET, POR and Software Reset, that is, they hold their
initialization values during reset.
Table 5 summarizes the state of output signals after reset.
Table 5.
SC16IS752_SC16IS762
Product data sheet
Output signals after reset
Signal
Reset state
TX
HIGH
RTS
HIGH
I/Os
inputs
IRQ
HIGH by external pull-up
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Rev. 9 — 22 March 2012
© NXP B.V. 2012. All rights reserved.
13 of 60
SC16IS752; SC16IS762
NXP Semiconductors
Dual UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
7.5 Interrupts
The SC16IS752/SC16IS762 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.
Table 6.
Summary of interrupt control functions
IIR[5:0]
Priority Interrupt type
level
Interrupt source
00 0001
none
none
none
00 0110
1
receiver line status
Overrun Error (OE), Framing Error (FE), Parity Error
(PE), or Break Interrupt (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
change of state of modem input pins
11 0000
5
I/O pins
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)
It is important to note that for the framing error, parity error, and break conditions, Line
Status Register bit 7 (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.
SC16IS752_SC16IS762
Product data sheet
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Rev. 9 — 22 March 2012
© NXP B.V. 2012. All rights reserved.
14 of 60
SC16IS752; SC16IS762
NXP Semiconductors
Dual 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 8 shows Interrupt mode operation.
IIR
read IIR
IRQ
HOST
IER
1
1
THR
1
1
RHR
002aab042
Fig 8.
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 9 shows FIFO Polled
mode operation.
LSR
read LSR
HOST
IER
0
THR
0
0
0
RHR
002aab043
Fig 9.
SC16IS752_SC16IS762
Product data sheet
FIFO Polled mode operation
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Rev. 9 — 22 March 2012
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Dual UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
7.6 Sleep mode
Sleep mode is an enhanced feature of the SC16IS752/SC16IS762 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 SC16IS752/SC16IS762 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 10. The output frequency of the baud rate generator is 16 the baud
rate. The formula for the divisor is:
crystal input frequency
XTAL1
-----------------------------------------------------------------------------------
prescaler
divisor = ----------------------------------------------------------------------------------------desired baud rate 16
(1)
where:
prescaler = 1, when MCR[7] is set to logic 0 after reset (divide-by-1 clock selected)
prescaler = 4, when MCR[7] is set to logic 1 after reset (divide-by-4 clock selected).
Remark: The default value of prescaler after reset is divide-by-1.
SC16IS752_SC16IS762
Product data sheet
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Rev. 9 — 22 March 2012
© NXP B.V. 2012. All rights reserved.
16 of 60
SC16IS752; SC16IS762
NXP Semiconductors
Dual UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
Figure 10 shows the internal prescaler and baud rate generator circuitry.
PRESCALER
LOGIC
(DIVIDE-BY-1)
XTAL1
XTAL2
INTERNAL
OSCILLATOR
LOGIC
MCR[7] = 0
input clock
PRESCALER
LOGIC
(DIVIDE-BY-4)
reference
clock
BAUD RATE
GENERATOR
LOGIC
internal
baud rate
clock for
transmitter
and receiver
MCR[7] = 1
002aaa233
Fig 10. Prescaler and baud rate generator block diagram
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 11 shows the crystal clock circuit reference.
Table 7.
SC16IS752_SC16IS762
Product data sheet
Baud rates using a 1.8432 MHz crystal
Desired baud rate
(bit/s)
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
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Rev. 9 — 22 March 2012
© NXP B.V. 2012. All rights reserved.
17 of 60
SC16IS752; SC16IS762
NXP Semiconductors
Dual UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
Table 8.
Baud rates using a 3.072 MHz crystal
Desired baud rate
(bit/s)
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
XTAL1
XTAL2
X1
1.8432 MHz
C1
22 pF
C2
33 pF
002aab325
Fig 11. Crystal oscillator circuit reference
SC16IS752_SC16IS762
Product data sheet
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Rev. 9 — 22 March 2012
© NXP B.V. 2012. All rights reserved.
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SC16IS752; SC16IS762
NXP Semiconductors
Dual 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.
Table 9.
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
SC16IS752_SC16IS762
Product data sheet
Register map - read/write properties
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)[2]
Transmission Control Register[2]
TCR
Transmission Control Register
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
I/O pin Direction register
I/O pin Direction register
IOState
I/O pins State register
n/a
IOIntEna
I/O Interrupt Enable register
Interrupt Enable register
IOControl
I/O pins Control register
I/O pins Control register
EFCR
Extra Features Control Register
Extra Features Control Register
(DLL)[3]
Divisor Latch LSB[3]
DLL
Divisor Latch LSB
DLH
Divisor Latch MSB (DLH)[3]
Divisor Latch MSB[3]
EFR
Enhanced Features Register (EFR)[4]
Enhanced Features Register[4]
XON1
Xon1
word[4]
Xon1 word[4]
XON2
Xon2 word[4]
Xon2 word[4]
XOFF1
Xoff1 word[4]
Xoff1 word[4]
XOFF2
Xoff2 word[4]
Xoff2 word[4]
[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]
Accessible only when LCR[7] is logic 1.
[4]
Accessible only when LCR is set to 1011 1111b (0xBF).
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Rev. 9 — 22 March 2012
© NXP B.V. 2012. All rights reserved.
19 of 60
xxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxx x x x xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxx xx xx xxxxx
xxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxx xxxxxx xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxx x x
xxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxx xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxx
xxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxx xxx
Register
address
NXP Semiconductors
SC16IS752_SC16IS762
Product data sheet
Table 10.
SC16IS752/SC16IS762 internal registers
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
Sleep
mode[2]
modem status receive line
interrupt
status
interrupt
THR empty
interrupt
RX data
available
interrupt
R/W
CTS interrupt RTS interrupt
enable[2]
enable[2]
0x02
FCR
RX trigger
level (MSB)
RX trigger
level (LSB)
TX trigger
TX trigger
reserved[3]
[2]
[2]
level (MSB)
level (LSB)
TX FIFO
reset[4]
RX FIFO
reset[4]
FIFO enable
W
0x02
IIR[5]
FIFO enable
FIFO enable
interrupt
interrupt
interrupt
priority bit 4[2] priority bit 3[2] priority bit 2
interrupt
priority bit 1
interrupt
priority bit 0
interrupt
status
R
0x03
LCR
divisor latch
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 RTS
enable[2]
DTR (IO5)
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
RI
DSR
CTS
CD
RI
DSR
CTS
R
0x07
SPR
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
R/W
0x06
TCR[6]
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
R/W
0x07
TLR[6]
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[7]
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
R/W
0x0B
IOState[7]
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
R/W
0x0C
IOIntEna [7]
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[7]
reserved[3]
reserved[3]
reserved[3]
reserved[3]
UART
I/O[3:0] or
software reset RIB, CDB,
DTRB, DSRB
0x0F
EFCR
IrDA mode
(slow/ fast)[8]
reserved[3]
auto RS-485
RTS output
inversion
auto RS-485 reserved[3]
RTS direction
control
transmitter
disable
I/O[7:4] or
latch
RIA, CDA,
DTRA, DSRA
R/W
receiver
disable
R/W
9-bit mode
enable
SC16IS752; SC16IS762
20 of 60
© NXP B.V. 2012. All rights reserved.
IER
Dual UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
Rev. 9 — 22 March 2012
All information provided in this document is subject to legal disclaimers.
0x01
Xoff[2]
xxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxx x x x xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxx xx xx xxxxx
xxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxx xxxxxx xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxx x x
xxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxx xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxx
xxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxx xxx
Register
address
SC16IS752/SC16IS762 internal registers …continued
Register
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
R/W
NXP Semiconductors
SC16IS752_SC16IS762
Product data sheet
Table 10.
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 software flow R/W
control bit 1
control bit 0
0x04
XON1
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
R/W
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
These registers are accessible only when LCR[7] = logic 0.
[2]
This bit can only be modified if register bit EFR[4] is enabled.
[3]
These bits are reserved and should be set to logic 0.
[4]
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.
[5]
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.
[6]
These registers are accessible only when EFR[4] = logic 1, and MCR[2] = logic 1.
[7]
These registers apply to both channels.
[8]
IrDA mode slow/fast for SC16IS762, slow only for SC16IS752.
[9]
The Special Register set is accessible only when LCR[7] = logic 1 and LCR is not 0xBF.
[10] Enhanced Features Registers are only accessible when LCR = 0xBF.
21 of 60
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SC16IS752; SC16IS762
[1]
Dual UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
Rev. 9 — 22 March 2012
All information provided in this document is subject to legal disclaimers.
0x05
SC16IS752; SC16IS762
NXP Semiconductors
Dual UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
8.1 Receive Holding Register (RHR)
The receiver section consists of the Receive Holding Register (RHR) and the Receive
Shift Register (RSR). The RHR is actually a 64-byte FIFO. The RSR receives serial data
from the RX terminal. 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
terminal. If the FIFO is disabled, location zero of the FIFO is used to store the byte.
Characters are lost if overflow occurs.
8.3 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 11 shows Interrupt Enable Register bit settings.
Table 11.
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.
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 or bit 2 (in Table 29) 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
SC16IS752_SC16IS762
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 9 — 22 March 2012
© NXP B.V. 2012. All rights reserved.
22 of 60
SC16IS752; SC16IS762
NXP Semiconductors
Dual UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
Table 11.
Interrupt Enable Register bits description …continued
Bit
Symbol
Description
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
[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.
8.4 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 12 shows FIFO Control Register bit settings.
Table 12.
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
[1]
SC16IS752_SC16IS762
Product data sheet
FIFO reset logic requires at least two XTAL1 clocks, therefore, they cannot be reset without the presence of
the XTAL1 clock.
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Dual UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
8.5 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 13 shows Interrupt Identification Register bit settings.
Table 13.
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 14.
0
IIR[0]
Interrupt status.
logic 0 = an interrupt is pending
logic 1 = no interrupt is pending
Table 14.
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
Receive 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]
5
1
1
0
0
0
0
input pin change of state[1]
6
0
1
0
0
0
0
received Xoff signal/special
character
7
1
0
0
0
0
0
CTS, RTS change of state
from active (LOW) to
inactive (HIGH)
[1]
Modem interrupt status must be read via MSR register and GPIO interrupt status must be read via IOState
register.
8.6 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 15
shows the Line Control Register bit settings.
Table 15.
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
SC16IS752_SC16IS762
Product data sheet
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Dual UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
Table 15.
Line Control Register bits description …continued
Bit
Symbol
Description
5
LCR[5]
Set parity. LCR[5] selects the forced parity format (if LCR[3] = logic 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] = logic 1)
logic 1 = even parity is generated (if LCR[3] = logic 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]
Table 16.
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 17.
Product data sheet
LCR[2] stop bit length
LCR[2]
Word length (bits)
Stop bit length (bit times)
0
5, 6, 7, 8
1
1
5
11⁄2
1
6, 7, 8
2
Table 18.
SC16IS752_SC16IS762
Word length bits 1, 0. These two bits specify the word length to be
transmitted or received (see Table 18).
LCR[1:0] word length
LCR[1]
LCR[0]
Word length (bits)
0
0
5
0
1
6
1
0
7
1
1
8
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Dual UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
8.7 Modem Control Register (MCR)
The MCR controls the interface with the mode, data set, or peripheral device that is
emulating the modem. Table 19 shows Modem Control Register bit settings.
Table 19.
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. If GPIO5 or GPIO1 is selected as DTR modem pin through
IOControl register bit 1 or bit 2, the state of DTR pin can be controlled as
below. Writing to IOState bit 5 or bit 1 will not have any effect on the DTR
pin.
logic 0 = force DTR output to inactive (HIGH)
logic 1 = force DTR output to active (LOW)
[1]
SC16IS752_SC16IS762
Product data sheet
MCR[7:5] and MCR[2] can only be modified when EFR[4] is set, that is, EFR[4] is a write enable.
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Dual UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
8.8 Line Status Register (LSR)
Table 20 shows the Line Status Register bit settings.
Table 20.
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
(RX was LOW for one character time frame)
3
LSR[3]
Framing error.
logic 0 = no framing error in data being read from RX FIFO (normal
default condition)
logic 1 = framing error occurred in data being read from RX FIFO
(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
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.
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Dual UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
8.9 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 21 shows Modem Status Register bit settings per
channel.
Table 21.
Modem Status Register bits description
Bit
Symbol
Description
7
MSR[7]
CD (active HIGH, logical 1). If GPIO6 or GPIO2 is selected as CD
modem pin through IOControl register bit 1 or bit 2, the state of CD pin
can be read from this bit. This bit is the complement of the CD input.
Reading IOState bit 6 or bit 2 does not reflect the true state of CD pin.
6
MSR[6]
RI (active HIGH, logical 1). If GPIO7 or GPIO3 is selected as RI modem
pin through IOControl register bit 1 or bit 2, the state of RI pin can be
read from this bit. This bit is the complement of the RI input. Reading
IOState bit 7 or bit 3 does not reflect the true state of RI pin.
5
MSR[5]
DSR (active HIGH, logical 1). If GPIO4 or GPIO0 is selected as DSR
modem pin through IOControl register bit 1 or bit 2, the state of DSR pin
can be read from this bit. This bit is the complement of the DSR input.
Reading IOState bit 4 or bit 0 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. Indicates that CD input has changed state. Cleared on a read.
2
MSR[2]
RI. Indicates that RI input has changed state from LOW to HIGH.
Cleared on a read.
1
MSR[1]
DSR. 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.
Remark: The primary inputs RI, CD, CTS, DSR are all active LOW.
8.10 Scratchpad Register (SPR)
The SC16IS752/SC16IS762 provides a temporary data register to store 8 bits of user
information.
SC16IS752_SC16IS762
Product data sheet
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Dual UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
8.11 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 22 shows Transmission Control Register bit
settings. If TCR bits are cleared, then selectable trigger levels in FCR are used in place of
TCR.
Table 22.
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
TCR trigger levels are available from 0 bytes to 60 characters with a granularity of four.
Remark: TCR can only be written to when EFR[4] = logic 1 and MCR[2] = logic 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.
8.12 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 four. Table 23 shows Trigger Level Register bit settings.
Table 23.
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
Remark: TLR can only be written to when EFR[4] = logic 1 and MCR[2] = logic 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 N⁄4, where N is the desired trigger level.
When the trigger level setting in TLR is zero, the SC16IS752/SC16IS762 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
‘00’.
SC16IS752_SC16IS762
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Dual UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
8.13 Transmitter FIFO Level register (TXLVL)
This register is a read-only register. It reports the number of spaces available in the
transmit FIFO.
Table 24.
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)
8.14 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.
Table 25.
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)
8.15 Programmable I/O pins Direction register (IODir)
This register is used to program the I/O pins direction. Bit 0 to bit 7 controls GPIO0 to
GPIO7.
Table 26.
IODir register bits description
Bit
Symbol
Description
7:0
IODir
Set GPIO pins [7:0] to input or output.
0 = input
1 = output
8.16 Programmable I/O pins State register (IOState)
When ‘read’, this register returns the actual state of all I/O pins. When ‘write’, each
register bit will be transferred to the corresponding I/O pin programmed as output.
Table 27.
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
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8.17 I/O Interrupt Enable register (IOIntEna)
This register enables the interrupt due to a change in the I/O configured as inputs. If
GPIO[7:4] or GPIO[3:0] are programmed as modem pins, their interrupt generation must
be enabled via IER[3]. In this case, IOIntEna will have no effect on GPIO[7:4] or
GPIO[3:0].
Table 28.
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
8.18 I/O Control register (IOControl)
Table 29.
IOControl register bits description
Bit
Symbol
Description
7:4
reserved
These bits are reserved for future use.
3
SRESET
Software Reset. A write to this bit will reset the device. Once the
device is reset this bit is automatically set to logic 0.
2
GPIO[3:0] or
RIB, CDB,
DTRB, DSRB
This bit programs GPIO[3:0] as I/O pins or as modem pins.
GPIO[7:4] or
RIA, CDA,
DTRA, DSRA
This bit programs GPIO[7:4] as I/O pins or as modem pins.
IOLATCH
Enable/disable inputs latching.
1
0
0 = I/O pins
1 = GPIO[3:0] emulate RIB, CDB, DTRB, DSRB
0 = I/O pins
1 = GPIO[7:4] emulate RIA, CDA, DTRA, DSRA
0 = input value 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.
Remark: As I/O pins, the direction, state, and interrupt enable of GPIO 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 the DTR pin can be controlled by MCR[0]. Also,
if modem status interrupt bit is enabled, IER[3], a change of state on RI, CD, DSR pins will
trigger a modem interrupt. The IODir, IOState, and IOIntEna registers will not have any
effect on these three pins.
SC16IS752_SC16IS762
Product data sheet
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Dual UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
8.19 Extra Features Control Register (EFCR)
Table 30.
Extra Features Control Register bits description
Bit
Symbol
Description
7
IRDA MODE
IrDA mode.
0 = IrDA SIR, 3⁄16 pulse ratio, data rate up to 115.2 kbit/s
1 = IrDA SIR, 1⁄4 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 is set to 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
[1]
For SC16IS762 only.
8.20 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.
Note that DLL and DLH can only be written to before Sleep mode is enabled (before
IER[4] is set).
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8.21 Enhanced Features Register (EFR)
This 8-bit register enables or disables the enhanced features of the UART. Table 31
shows the Enhanced Features Register bit settings.
Table 31.
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])”.
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 de-asserts 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.
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 de-asserts 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).
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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 RTS mode the software would have to disable the hardware flow
control function.
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 XOFF2 contains the address
byte) the receiver will try to detect an address byte that matches the programmed
character in XOFF2. If the received byte is a data byte or an address byte that does not
match the programmed character in XOFF2, 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 bit 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[2]).
SC16IS752_SC16IS762
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Dual 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 12). 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 13). 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.
SDA
SCL
data line
stable;
data valid
change
of data
allowed
mba607
Fig 12. Bit transfer on the I2C-bus
SDA
SCL
S
P
START condition
STOP condition
mba608
Fig 13. START and STOP conditions
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 14). 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 15).
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Dual UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
acknowledgement signal
from receiver
SDA
MSB
SCL
0
S
1
6
7
8
0
1
2 to 7
ACK
START
condition
8
P
ACK
byte complete,
interrupt within receiver
STOP
condition
clock line held LOW
while interrupt is serviced
002aab012
Fig 14. Data transfer on the I2C-bus
data output
by transmitter
transmitter stays off of the bus
during the acknowledge clock
data output
by receiver
SCL from master
acknowledgement signal
from receiver
S
0
1
6
7
8
002aab013
START
condition
Fig 15. Acknowledge on the I2C-bus
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. When designing a system, it is necessary to take into account cases when
acknowledge is not received. This happens, for example, when the addressed device is
busy in a real-time operation. In such a case the master, after an appropriate ‘time-out’,
should abort the transfer by generating a STOP condition, allowing other transfers to take
place. These ‘other transfers’ could be initiated by other masters in a multimaster system,
or by this same master.
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.
SC16IS752_SC16IS762
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Dual UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
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.
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 zero indicates that the master is
transmitting (‘write’) and a one 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 16.
SDA
SCL
S
START
condition
0 to 6
address
7
8
0 to 6
R/W
ACK
data
7
8
0 to 6
ACK
data
7
8
P
ACK
STOP
condition
002aab046
Fig 16. A complete data transfer
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 16, 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 17. 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.
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Dual UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
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 occupies the bus for a long time, and thus preventing
other devices from initiating transfers.
data transferred
(n bytes + acknowledge)
master write:
S
SLAVE ADDRESS
START condition
W
write
A
DATA
acknowledge
A
DATA
acknowledge
A
P
acknowledge
STOP condition
data transferred
(n bytes + acknowledge)
master read:
S
SLAVE ADDRESS
START condition
R
read
A
DATA
acknowledge
A
DATA
acknowledge
NA
P
not
acknowledge
STOP condition
data transferred
(n bytes + acknowledge)
combined
formats:
S
SLAVE ADDRESS R/W
START condition
read or
write
A
DATA
acknowledge
A
acknowledge
data transferred
(n bytes + acknowledge)
Sr
SLAVE ADDRESS R/W
repeated
START condition
read or
write
A
DATA
acknowledge
direction of transfer
may change at this point
A
P
acknowledge
STOP condition
002aab458
Fig 17. I2C-bus data formats
SC16IS752_SC16IS762
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Dual 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 SC16IS752/SC16IS762’s
address can be selected by using A1 and A0 pins. For example, if these 2 pins are
connected to VDD, then the SC16IS752/SC16IS762’s address is set to 0x90, and the
master communicates with it through this address.
Table 32.
SC16IS752/SC16IS762 address map
A1
A0
SC16IS752/SC16IS762 I2C address (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)
[1]
X = logic 0 for write cycle; X = logic 1 for read cycle.
10.4 Use of subaddresses
When a master communicates with the SC16IS752/SC16IS762 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.
A register write cycle is shown in Figure 18. 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 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.
SC16IS752_SC16IS762
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Dual UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
S
SLAVE ADDRESS
W
A
REGISTER ADDRESS(1)
A
nDATA
A
P
002aab047
White block: host to SC16IS752/SC16IS762
Grey block: SC16IS752/SC16IS762 to host
(1) See Table 33 for additional information.
Fig 18. Master writes to slave
The register read cycle (see Figure 19) 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.
S
SLAVE ADDRESS
W
REGISTER ADDRESS(1)
A
A
S
nDATA
SLAVE ADDRESS
A
LAST DATA
R
A
NA
P
002aab048
White block: host to SC16IS752/SC16IS762
Grey block: SC16IS752/SC16IS762 to host
(1) See Table 33 for additional information.
Fig 19. Master read from slave
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.
00 = channel A
01 = channel B
10 = reserved
11 = reserved
0
SC16IS752_SC16IS762
Product data sheet
-
not used
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Rev. 9 — 22 March 2012
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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
R/W
A3
A2
A1
A0
CH1 CH0
X
D7
D6
D5
D4
D3
D2
D1
D0
002aab433
R/W = 0; A[3:0] = register address; CH[1:0] = 00 for channel A; CH[1:0] = 01 for channel B
a. Register write
SCLK
SI
R/W
A3
A2
A1
A0
CH1 CH0
NXP Semiconductors
SI
11. SPI operation
SC16IS752_SC16IS762
Product data sheet
SCLK
X
D7
SO
D6
D5
D4
D3
D2
D1
D0
R/W = 1; A[3:0] = register address; CH[1:0] = 00 for channel A; CH[1:0] = 01 for channel B
b. Register read
SCLK
SI
R/W
A3
A2
A1
A0
CH1 CH0
X
D7
D6
D5
D4
D3
D2
D1
D0
D7
D6
D5
D4
D3
D2
D1
D0
002aab435
last bit(2)
002aab436
R/W = 0; A[3:0] = 0000; CH[1:0] = 00 for channel A; CH[1:0] = 01 for channel B
c. FIFO write cycle
SCLK
SI
R/W
A3
A2
A1
A0
CH1 CH0
X
D7
SO
D6
D5
D4
D3
D2
41 of 60
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R/W = 1; A[3:0] = 0000; CH[1:0] = 00 for channel A; CH[1:0] = 01 for channel B
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 20. SPI operation
D1
D0
D7
D6
D5
D4
D3
D2
D1
D0
SC16IS752; SC16IS762
last bit(1)
Dual UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
Rev. 9 — 22 March 2012
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002aab434
SC16IS752; SC16IS762
NXP Semiconductors
Dual UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
Table 34.
Register address byte (SPI)
Bit
Name
Function
7
R/W
Read/write.
1 = read from UART
0 = write to UART
6:3
A[3:0]
UART’s internal register select
2:1
CH1, CH0
Channel select.
00 = channel A
01 = channel B
10 = reserved
11 = reserved
0
-
not used
12. Limiting values
Table 35. Limiting values
In accordance with the Absolute Maximum Rating System (IEC 60134).
Symbol
Parameter
VDD
Conditions
Min
Max
Unit
supply voltage
0.3
+4.6
V
V
VI
input voltage
any input
0.3
+5.5[1]
II
input current
any input
10
+10
mA
IO
output current
any output
10
+10
mA
Ptot
total power dissipation
-
300
mW
P/out
power dissipation per
output
-
50
mW
Tamb
ambient temperature
40
+85
C
operating
VDD = 2.5 V 0.2 V
VDD = 3.3 V 0.3 V
Tj
junction temperature
Tstg
storage temperature
[1]
SC16IS752_SC16IS762
Product data sheet
operating
40
+95
C
-
+125
C
65
+150
C
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.
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Dual UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
13. Static characteristics
Table 36. Static characteristics
VDD = 2.5 V 0.2 V, Tamb = 40 C to +85 C; or VDD = 3.3 V 0.3 V, Tamb = 40 C to +95 C; unless otherwise specified.
Symbol
Parameter
Conditions
VDD = 2.5 V
VDD = 3.3 V
Unit
Min
Max
Min
Max
2.3
2.7
3.0
3.6
V
-
2.0
-
2.0
mA
1.6
5.5[1]
2.0
5.5[1]
V
-
0.6
-
0.8
V
-
1
-
1
A
-
3
-
3
pF
1.85
-
-
-
V
IOH = 4 mA
-
-
2.4
-
V
IOL = 1.6 mA
-
0.4
-
-
V
IOL = 4 mA
-
-
-
0.4
V
-
4
-
4
pF
Supplies
VDD
supply voltage
IDD
supply current
operating; no load;
X1 = 4 MHz
Inputs I2C/SPI, RX, CTS, RESET
VIH
HIGH-level input voltage
VIL
LOW-level input voltage
IL
leakage current
Ci
input capacitance
input; VI = 0 V or 5.5
V[1]
Outputs TX, RTS, SO
VOH
VOL
Co
HIGH-level output voltage
LOW-level output voltage
IOH = 400 A
output capacitance
Inputs/outputs GPIO0 to GPIO7
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
1.85
-
-
-
V
IOH = 4 mA
-
-
2.4
-
V
IOL = 1.6 mA
-
0.4
-
-
V
IOL = 4 mA
-
-
-
0.4
V
-
1
-
1
A
-
4
-
4
pF
IOL = 1.6 mA
-
0.4
-
-
V
IOL = 4 mA
-
-
-
0.4
V
-
4
-
4
pF
VOL
LOW-level output voltage
IL
leakage current
Co
output capacitance
IOH = 400 A
input; VI = 0 V or 5.5
V[1]
Output IRQ
VOL
Co
I2C-bus
LOW-level output voltage
output capacitance
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
IL
leakage current
input; VI = 0 V or 5.5 V[1]
-
10
-
10
A
Co
output capacitance
-
7
-
7
pF
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SC16IS752; SC16IS762
NXP Semiconductors
Dual UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
Table 36. Static characteristics …continued
VDD = 2.5 V 0.2 V, Tamb = 40 C to +85 C; or VDD = 3.3 V 0.3 V, Tamb = 40 C to +95 C; unless otherwise specified.
Symbol
I2C-bus
Parameter
Conditions
VDD = 2.5 V
VDD = 3.3 V
Min
Max
Min
Max
Unit
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
IL
leakage current
-
10
-
10
A
Ci
input capacitance
-
7
-
7
pF
1.8
5.5[1]
2.4
5.5[1]
V
-
0.45
-
0.6
V
30
+30
30
+30
A
-
3
-
3
pF
-
25
-
25
A
Clock input
input; VI = 0 V or 5.5 V[1]
XTAL1[2]
VIH
HIGH-level input voltage
VIL
LOW-level input voltage
IL
leakage current
Ci
input capacitance
input; VI = 0 V or 5.5
V[1]
Sleep current
IDD(sleep)
sleep mode supply current
inputs are at VDD or ground
[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.
SC16IS752_SC16IS762
Product data sheet
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NXP Semiconductors
Dual UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
14. Dynamic characteristics
Table 37. I2C-bus timing specifications[1]
All the timing limits are valid within the operating supply voltage, ambient temperature range and output load;
VDD = 2.5 V 0.2 V, Tamb = 40 C to +85 C; or VDD = 3.3 V 0.3 V, Tamb = 40 C to +95 C; VIL and VIH refer to input
voltage of VSS to VDD. All output load = 25 pF, except SDA output load = 400 pF.
Symbol
Parameter
Conditions
Standard-mode
I2C-bus
[2]
Fast-mode
I2C-bus
Min
Max
Min
Max
0
100
0
400
Unit
fSCL
SCL clock frequency
tBUF
bus free time between a STOP and START
condition
4.7
-
1.3
-
s
tHD;STA
hold time (repeated) START condition
4.0
-
0.6
-
s
tSU;STA
set-up time for a repeated START condition
4.7
-
0.6
-
s
tSU;STO
set-up time for STOP condition
4.7
-
0.6
-
s
tHD;DAT
data hold time
0
-
0
-
ns
tVD;ACK
data valid acknowledge time
-
0.6
-
0.6
s
tVD;DAT
data valid time
-
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
-
s
tHIGH
HIGH period of the SCL clock
4.0
-
0.6
-
s
SCL LOW to
data out valid
kHz
tf
fall time of both SDA and SCL signals
-
300
-
300
ns
tr
rise 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
0.5
-
0.5
-
s
td2
I2C-bus modem input interrupt valid time
0.2
-
0.2
-
s
td3
I2C-bus
0.2
-
0.2
-
s
td4
I2C input pin interrupt valid time
0.2
-
0.2
-
s
td5
I2C input pin interrupt clear time
0.2
-
0.2
-
s
td6
I2C-bus receive interrupt valid time
0.2
-
0.2
-
s
td7
I2C-bus
receive interrupt clear time
0.2
-
0.2
-
s
td8
I2C-bus
transmit interrupt clear time
1.0
-
0.5
-
s
modem input interrupt clear time
td15
SCL delay after reset
tw(rst)
reset pulse width
[3]
3
-
3
-
s
3
-
3
-
s
[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/documents/user_manual/UM10204.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]
2 XTAL1 clock cycles or 3 s, whichever is less.
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Dual UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
RESET
tw(rst)
td15
SCL
002aab437
Fig 21. SCL delay after reset
protocol
bit 7
MSB
(A7)
START
condition
(S)
tSU;STA
tLOW
bit 0
LSB
(R/W)
bit 6
(A6)
tHIGH
1/f
acknowledge
(A)
STOP
condition
(P)
SCL
SCL
tBUF
tf
tr
tSP
SDA
tSU;DAT
tHD;STA
tVD;ACK
tVD;DAT
tHD;DAT
tSU;STO
002aab489
Rise and fall times refer to VIL and VIH.
Fig 22. I2C-bus timing diagram
SDA
SLAVE ADDRESS
W
A
A IOSTATE REG.
A
A
DATA
td1
GPIOn
002aab255
Fig 23. Write to output
ACK to master
SDA
SLAVE ADDRESS
W
A
AMSR REGISTER
A
S
SLAVE ADDRESS
R
A
DATA
A
IRQ
td2
td3
MODEM pin
002aab256
Fig 24. Modem input pin interrupt
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Dual UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
ACK from slave
SLAVE ADDRESS
SDA
W
A
A IOSTATE REG.
ACK from slave
A
S
SLAVE ADDRESS
R
ACK from master
A
A
DATA
P
IRQ
td4
td5
GPIOn
002aab257
Fig 25. GPIO pin interrupt
RX
next
start
bit
stop
bit
start
bit
D0
D1
D2
D3
D4
D5
D6
D7
td6
IRQ
002aab258
Fig 26. Receive interrupt
SDA
SLAVE ADDRESS
W
A
A
A
RHR
S
R
SLAVE ADDRESS
A
A
DATA
P
IRQ
td7
002aab259
Fig 27. Receive interrupt clear
SDA
SLAVE ADDRESS
W
A
ATHR REGISTER
A
A
DATA
IRQ
td8
002aab260
Fig 28. Transmit interrupt clear
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Dual UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
Table 38. fXTAL dynamic characteristics
VDD = 2.5 V 0.2 V, Tamb = 40 C to +85 C; or VDD = 3.3 V 0.3 V, Tamb = 40 C to +95 C.
Symbol
Parameter
Conditions
tw1
clock pulse duration
HIGH level
tw2
clock pulse duration
LOW level
fXTAL
[1]
[2]
VDD = 2.5 V
[1][2]
oscillator/clock frequency
VDD = 3.3 V
Unit
Min
Max
Min
Max
10
-
6
-
ns
10
-
6
-
ns
-
48
-
80
MHz
Applies to external clock, crystal oscillator max. 24 MHz.
1
f XTAL = -----t w3
tw2
tw1
EXTERNAL
CLOCK
002aac020
tw3
Fig 29. External clock timing
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Dual UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
Table 39. SPI-bus timing specifications
All the timing limits are valid within the operating supply voltage, ambient temperature range and output load;
VDD = 2.5 V 0.2 V, Tamb = 40 C to +85 C; or VDD = 3.3 V 0.3 V, Tamb = 40 C to +95 C; VIL and VIH refer to input
voltage of VSS to VDD. All output load = 25 pF, unless otherwise specified.
Symbol
Parameter
Conditions
VDD = 2.5 V
Min
tTR
CS HIGH to SO 3-state
CL = 100 pF
VDD = 3.3 V
Max
Min
Unit
Max
-
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
-
25
-
20
ns
tDS
SI to SCLK setup time
10
-
10
-
ns
tDH
SI to SCLK hold time
10
-
10
-
ns
tCP
SCLK period
83
-
67
-
ns
tCH
SCLK HIGH time
30
-
25
-
ns
tCL
SCLK LOW time
30
-
25
-
ns
CL = 100 pF
tCL + tCH
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
-
s
CS
tCSH
tCL
tCSS
tCH
tCSH
tCSW
SCLK
tDH
tDS
SI
tDO
tTR
SO
002aab066
Fig 30. Detailed SPI-bus timing
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Dual UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
CS
SCLK
SI
R/W
A3
A2
A1
CH1 CH0
A0
X
D7
D6
D5
D4
D3
D2
D1
D0
td9
GPIOx
002aab438
R/W = 0; A[3:0] = IOState (0x0B); CH[1:0] = 00 for channel A; CH[1:0] = 01 for channel B
Fig 31. SPI write IOState to GPIO switch
CS
SCLK
SI
R/W
A3
A2
A1
A0
CH1 CH0
X
D7
D6
D5
D4
D3
D2
D1
D0
td10
DTR (GPIO5)
002aab439
R/W = 0; A[3:0] = MCR (0x04); CH[1:0] = 00 for channel A; CH[1:0] = 01 for channel B
Fig 32. SPI write MCR to DTR output switch
CS
SCLK
SI
R/W
A3
A2
A1
A0
CH1 CH0
X
D7
D6
D5
D4
D3
D2
D1
D0
SO
td11
IRQ
002aab440
R/W = 0; A[3:0] = THR (0x00); CH[1:0] = 00 for channel A; CH[1:0] = 01 for channel B
Fig 33. SPI write THR to clear TX interrupt
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Dual UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
CS
SCLK
SI
R/W
A3
A2
A1
A0
CH1 CH0
X
D7
SO
D6
D5
D4
D3
D2
D1
D0
td12
IRQ
002aab441
R/W = 1; A[3:0] = MSR (0x06); CH[1:0] = 00 for channel A; CH[1:0] = 01 for channel B
Fig 34. Read MSR to clear modem interrupt
CS
SCLK
SI
R/W
A3
A2
A1
A0
CH1 CH0
X
D7
SO
D6
D5
D4
D3
D2
D1
D0
td13
IRQ
002aab442
R/W = 1; A[3:0] = IOState (0x0B); CH[1:0] = 00 for channel A; CH[1:0] = 01 for channel B
Fig 35. Read IOState to clear GPIO interrupt
CS
SCLK
SI
R/W
A3
A2
A1
A0
CH1 CH0
X
D7
SO
D6
D5
D4
D3
D2
D1
D0
td14
IRQ
002aab443
R/W = 1; A[3:0] = RHR (0x00); CH[1:0] = 00 for channel A; CH[1:0] = 01 for channel B
Fig 36. Read RHR to clear RX interrupt
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Dual UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
15. Package outline
TSSOP28: plastic thin shrink small outline package; 28 leads; body width 4.4 mm
D
SOT361-1
E
A
X
c
HE
y
v M A
Z
15
28
Q
A2
(A 3)
A1
pin 1 index
A
θ
Lp
1
L
14
detail X
w M
bp
e
0
2.5
5 mm
scale
DIMENSIONS (mm are the original dimensions)
UNIT
A
max.
A1
A2
A3
bp
c
D (1)
E (2)
e
HE
L
Lp
Q
v
w
y
Z (1)
θ
mm
1.1
0.15
0.05
0.95
0.80
0.25
0.30
0.19
0.2
0.1
9.8
9.6
4.5
4.3
0.65
6.6
6.2
1
0.75
0.50
0.4
0.3
0.2
0.13
0.1
0.8
0.5
8o
o
0
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.
OUTLINE
VERSION
SOT361-1
Fig 37.
REFERENCES
IEC
JEDEC
JEITA
EUROPEAN
PROJECTION
ISSUE DATE
99-12-27
03-02-19
MO-153
Package outline SOT361-1 (TSSOP28)
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Dual UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
HVQFN32: plastic thermal enhanced very thin quad flat package; no leads;
32 terminals; body 5 x 5 x 0.85 mm
A
B
D
SOT617-1
terminal 1
index area
A
A1
E
c
detail X
C
e1
e
1/2
e b
9
y
y1 C
v M C A B
w M C
16
L
17
8
e
e2
Eh
1/2
1
terminal 1
index area
e
24
32
25
X
Dh
0
2.5
5 mm
scale
DIMENSIONS (mm are the original dimensions)
UNIT
A(1)
max.
A1
b
c
D (1)
Dh
E (1)
Eh
e
e1
e2
L
v
w
y
y1
mm
1
0.05
0.00
0.30
0.18
0.2
5.1
4.9
3.25
2.95
5.1
4.9
3.25
2.95
0.5
3.5
3.5
0.5
0.3
0.1
0.05
0.05
0.1
Note
1. Plastic or metal protrusions of 0.075 mm maximum per side are not included.
REFERENCES
OUTLINE
VERSION
IEC
JEDEC
JEITA
SOT617-1
---
MO-220
---
EUROPEAN
PROJECTION
ISSUE DATE
01-08-08
02-10-18
Fig 38. Package outline SOT617-1 (HVQFN32)
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16. Handling information
All input and output pins are protected against ElectroStatic Discharge (ESD) under
normal handling. When handling ensure that the appropriate precautions are taken as
described in JESD625-A or equivalent standards.
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:
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Dual 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 39) 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 40 and 41
Table 40.
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 41.
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
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 39.
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Dual UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
temperature
maximum peak temperature
= MSL limit, damage level
minimum peak temperature
= minimum soldering temperature
peak
temperature
time
001aac844
MSL: Moisture Sensitivity Level
Fig 39. Temperature profiles for large and small components
For further information on temperature profiles, refer to Application Note AN10365
“Surface mount reflow soldering description”.
18. Appendix
18.1 Errata for Rev. E added 12 August 2011
18.1.1 IrDA wake-up
In Rev. D, the UART cannot wake up through RX pin once the UART is put to sleep by the
host.
18.1.2 Clearing of RX FIFO overflow
In Rev. D, once the receive FIFO overflows, the receive FIFO cannot be cleared with FIFO
reset command if the UART is continuously receiving data.
18.1.3 Interrupt priority encoder
When the edge of the IOR signal (an internal signal that reads IIR register) comes close to
the X1 clock that generates the interrupt, the value of the Interrupt Indication Register (IIR)
might not be correct. This issue might occur if the X1 clock is very slow and the host read
operation is very fast in response to the interrupt from the UART.
18.1.4 Time-out interrupt
If the host reads the receive FIFO at the at the same time as a time-out interrupt condition
happens, the host might read 0xCC (time-out) in the Interrupt Indication Register (IIR), but
bit 0 of the Line Status Register (LSR) is not set (means there is not data in the
receive FIFO). This is a conflict of the receive FIFO status when IIR = 0xCC (time-out), it
indicates that there are data in the receive FIFO, but LSR bit 0 = 0 indicates otherwise.
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Dual UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
19. Abbreviations
Table 42.
Abbreviations
Acronym
Description
CPU
Central Processing Unit
DLL
Divisor Latch LSB
DLH
Divisor Latch MSB
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
SPR
ScratchPad Register
UART
Universal Asynchronous Receiver/Transmitter
20. Revision history
Table 43.
Revision history
Document ID
Release date
Data sheet status
Change notice
Supersedes
SC16IS752_SC16IS762 v.9
20120322
Product data sheet
-
SC16IS752_SC16IS762 v.8
Modifications:
•
Table 6 “Summary of interrupt control functions”: IIR[5:0] for interrupt type “I/O pins”
corrected from “00 1110” to “11 0000'
SC16IS752_SC16IS762 v.8
20110901
Product data sheet
-
SC16IS752_SC16IS762 v.7
SC16IS752_SC16IS762 v.7
20080519
Product data sheet
-
SC16IS752_SC16IS762 v.6
SC16IS752_SC16IS762 v.6
20061219
Product data sheet
-
SC16IS752_SC16IS762 v.5
SC16IS752_SC16IS762 v.5
20061128
Product data sheet
-
SC16IS752_SC16IS762 v.4
SC16IS752_SC16IS762 v.4
20061013
Product data sheet
-
SC16IS752_SC16IS762 v.3
SC16IS752_SC16IS762 v.3
20060707
Product data sheet
-
SC16IS752_SC16IS762 v.2
SC16IS752_SC16IS762 v.2
20060330
Product data sheet
-
SC16IS752_SC16IS762 v.1
SC16IS752_SC16IS762 v.1
20060104
Product data sheet
-
-
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Product data sheet
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Dual UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
21. Legal information
21.1 Data sheet status
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.
[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.
21.2 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.
Product specification — The information and data provided in a Product
data sheet shall define the specification of the product as agreed between
NXP Semiconductors and its customer, unless NXP Semiconductors and
customer have explicitly agreed otherwise in writing. In no event however,
shall an agreement be valid in which the NXP Semiconductors product is
deemed to offer functions and qualities beyond those described in the
Product data sheet.
21.3 Disclaimers
Limited warranty and liability — 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. NXP Semiconductors takes no
responsibility for the content in this document if provided by an information
source outside of NXP Semiconductors.
In no event shall NXP Semiconductors be liable for any indirect, incidental,
punitive, special or consequential damages (including - without limitation - lost
profits, lost savings, business interruption, costs related to the removal or
replacement of any products or rework charges) whether or not such
damages are based on tort (including negligence), warranty, breach of
contract or any other legal theory.
Notwithstanding any damages that customer might incur for any reason
whatsoever, NXP Semiconductors’ aggregate and cumulative liability towards
customer for the products described herein shall be limited in accordance
with the Terms and conditions of commercial sale of NXP Semiconductors.
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.
SC16IS752_SC16IS762
Product data sheet
Suitability for use — NXP Semiconductors products are not designed,
authorized or warranted to be suitable for use in life support, life-critical or
safety-critical systems or 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 and its suppliers accept 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.
Customers are responsible for the design and operation of their applications
and products using NXP Semiconductors products, and NXP Semiconductors
accepts no liability for any assistance with applications or customer product
design. It is customer’s sole responsibility to determine whether the NXP
Semiconductors product is suitable and fit for the customer’s applications and
products planned, as well as for the planned application and use of
customer’s third party customer(s). Customers should provide appropriate
design and operating safeguards to minimize the risks associated with their
applications and products.
NXP Semiconductors does not accept any liability related to any default,
damage, costs or problem which is based on any weakness or default in the
customer’s applications or products, or the application or use by customer’s
third party customer(s). Customer is responsible for doing all necessary
testing for the customer’s applications and products using NXP
Semiconductors products in order to avoid a default of the applications and
the products or of the application or use by customer’s third party
customer(s). NXP does not accept any liability in this respect.
Limiting values — Stress above one or more limiting values (as defined in
the Absolute Maximum Ratings System of IEC 60134) will cause permanent
damage to the device. Limiting values are stress ratings only and (proper)
operation of the device at these or any other conditions above those given in
the Recommended operating conditions section (if present) or the
Characteristics sections of this document is not warranted. Constant or
repeated exposure to limiting values will permanently and irreversibly affect
the quality and reliability of the device.
Terms and conditions of commercial 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, unless otherwise
agreed in a valid written individual agreement. In case an individual
agreement is concluded only the terms and conditions of the respective
agreement shall apply. NXP Semiconductors hereby expressly objects to
applying the customer’s general terms and conditions with regard to the
purchase of NXP Semiconductors products by customer.
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.
All information provided in this document is subject to legal disclaimers.
Rev. 9 — 22 March 2012
© NXP B.V. 2012. All rights reserved.
58 of 60
SC16IS752; SC16IS762
NXP Semiconductors
Dual UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
Export control — This document as well as the item(s) described herein
may be subject to export control regulations. Export might require a prior
authorization from competent authorities.
Non-automotive qualified products — Unless this data sheet expressly
states that this specific NXP Semiconductors product is automotive qualified,
the product is not suitable for automotive use. It is neither qualified nor tested
in accordance with automotive testing or application requirements. NXP
Semiconductors accepts no liability for inclusion and/or use of
non-automotive qualified products in automotive equipment or applications.
In the event that customer uses the product for design-in and use in
automotive applications to automotive specifications and standards, customer
(a) shall use the product without NXP Semiconductors’ warranty of the
product for such automotive applications, use and specifications, and (b)
whenever customer uses the product for automotive applications beyond
NXP Semiconductors’ specifications such use shall be solely at customer’s
own risk, and (c) customer fully indemnifies NXP Semiconductors for any
liability, damages or failed product claims resulting from customer design and
use of the product for automotive applications beyond NXP Semiconductors’
standard warranty and NXP Semiconductors’ product specifications.
Translations — A non-English (translated) version of a document is for
reference only. The English version shall prevail in case of any discrepancy
between the translated and English versions.
21.4 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.
22. Contact information
For more information, please visit: http://www.nxp.com
For sales office addresses, please send an email to: salesaddresses@nxp.com
SC16IS752_SC16IS762
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 9 — 22 March 2012
© NXP B.V. 2012. All rights reserved.
59 of 60
SC16IS752; SC16IS762
NXP Semiconductors
Dual UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
23. Contents
1
2
2.1
2.2
2.3
3
4
5
6
6.1
6.2
7
7.1
7.2
7.2.1
7.2.2
7.3
7.3.1
7.3.2
7.4
7.5
7.5.1
7.5.2
7.6
7.7
7.8
8
8.1
8.2
8.3
8.4
8.5
8.6
8.7
8.8
8.9
8.10
8.11
8.12
8.13
8.14
8.15
8.16
General description . . . . . . . . . . . . . . . . . . . . . . 1
Features and benefits . . . . . . . . . . . . . . . . . . . . 1
General features . . . . . . . . . . . . . . . . . . . . . . . . 1
I2C-bus features . . . . . . . . . . . . . . . . . . . . . . . . 2
SPI features . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Ordering information . . . . . . . . . . . . . . . . . . . . . 3
Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Pinning information . . . . . . . . . . . . . . . . . . . . . . 5
Pinning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Pin description . . . . . . . . . . . . . . . . . . . . . . . . . 6
Functional description . . . . . . . . . . . . . . . . . . . 8
Trigger levels . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Hardware flow control . . . . . . . . . . . . . . . . . . . . 8
Auto-RTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Auto-CTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Software flow control . . . . . . . . . . . . . . . . . . . 10
Receive flow control . . . . . . . . . . . . . . . . . . . . 11
Transmit flow control. . . . . . . . . . . . . . . . . . . . 11
Hardware Reset, Power-On Reset (POR) and
Software Reset . . . . . . . . . . . . . . . . . . . . . . . . 13
Interrupts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Interrupt mode operation . . . . . . . . . . . . . . . . 15
Polled mode operation . . . . . . . . . . . . . . . . . . 15
Sleep mode . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Break and time-out conditions . . . . . . . . . . . . 16
Programmable baud rate generator . . . . . . . . 16
Register descriptions . . . . . . . . . . . . . . . . . . . 19
Receive Holding Register (RHR) . . . . . . . . . . 22
Transmit Holding Register (THR) . . . . . . . . . . 22
Interrupt Enable Register (IER) . . . . . . . . . . . 22
FIFO Control Register (FCR) . . . . . . . . . . . . . 23
Interrupt Identification Register (IIR). . . . . . . . 24
Line Control Register (LCR) . . . . . . . . . . . . . . 24
Modem Control Register (MCR) . . . . . . . . . . . 26
Line Status Register (LSR) . . . . . . . . . . . . . . . 27
Modem Status Register (MSR) . . . . . . . . . . . . 28
Scratchpad Register (SPR) . . . . . . . . . . . . . . 28
Transmission Control Register (TCR). . . . . . . 29
Trigger Level Register (TLR) . . . . . . . . . . . . . 29
Transmitter FIFO Level register (TXLVL) . . . . 30
Receiver FIFO Level register (RXLVL) . . . . . . 30
Programmable I/O pins Direction register
(IODir) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Programmable I/O pins State register
(IOState) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
8.17
8.18
8.19
8.20
8.21
9
9.1
9.2
9.3
9.3.1
9.3.2
10
10.1
10.2
10.3
10.4
11
12
13
14
15
16
17
17.1
17.2
17.3
17.4
18
18.1
18.1.1
18.1.2
18.1.3
18.1.4
19
20
21
21.1
21.2
21.3
21.4
22
23
I/O Interrupt Enable register (IOIntEna) . . . . .
I/O Control register (IOControl) . . . . . . . . . . .
Extra Features Control Register (EFCR) . . . .
Division registers (DLL, DLH) . . . . . . . . . . . .
Enhanced Features Register (EFR). . . . . . . .
RS-485 features . . . . . . . . . . . . . . . . . . . . . . . .
Auto RS-485 RTS control . . . . . . . . . . . . . . .
RS-485 RTS output inversion . . . . . . . . . . . .
Auto RS-485 . . . . . . . . . . . . . . . . . . . . . . . . .
Normal multidrop mode . . . . . . . . . . . . . . . . .
Auto address detection . . . . . . . . . . . . . . . . .
I2C-bus operation . . . . . . . . . . . . . . . . . . . . . .
Data transfers . . . . . . . . . . . . . . . . . . . . . . . .
Addressing and transfer formats . . . . . . . . . .
Addressing . . . . . . . . . . . . . . . . . . . . . . . . . . .
Use of subaddresses . . . . . . . . . . . . . . . . . . .
SPI operation . . . . . . . . . . . . . . . . . . . . . . . . . .
Limiting values . . . . . . . . . . . . . . . . . . . . . . . .
Static characteristics . . . . . . . . . . . . . . . . . . .
Dynamic characteristics. . . . . . . . . . . . . . . . .
Package outline. . . . . . . . . . . . . . . . . . . . . . . .
Handling information . . . . . . . . . . . . . . . . . . .
Soldering of SMD packages . . . . . . . . . . . . . .
Introduction to soldering. . . . . . . . . . . . . . . . .
Wave and reflow soldering. . . . . . . . . . . . . . .
Wave soldering . . . . . . . . . . . . . . . . . . . . . . .
Reflow soldering . . . . . . . . . . . . . . . . . . . . . .
Appendix . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Errata for Rev. E added 12 August 2011 . . . .
IrDA wake-up . . . . . . . . . . . . . . . . . . . . . . . . .
Clearing of RX FIFO overflow . . . . . . . . . . . .
Interrupt priority encoder . . . . . . . . . . . . . . . .
Time-out interrupt. . . . . . . . . . . . . . . . . . . . . .
Abbreviations . . . . . . . . . . . . . . . . . . . . . . . . .
Revision history . . . . . . . . . . . . . . . . . . . . . . .
Legal information . . . . . . . . . . . . . . . . . . . . . .
Data sheet status . . . . . . . . . . . . . . . . . . . . . .
Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . .
Disclaimers . . . . . . . . . . . . . . . . . . . . . . . . . .
Trademarks . . . . . . . . . . . . . . . . . . . . . . . . . .
Contact information . . . . . . . . . . . . . . . . . . . .
Contents. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31
31
32
32
33
33
33
33
34
34
34
35
35
37
39
39
41
42
43
45
52
54
54
54
54
54
55
56
56
56
56
56
56
57
57
58
58
58
58
59
59
60
Please be aware that important notices concerning this document and the product(s)
described herein, have been included in section ‘Legal information’.
© NXP B.V. 2012.
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: 22 March 2012
Document identifier: SC16IS752_SC16IS762