SC16C752BIB48,128 [NXP]

SC16C752B - 5 V, 2.2 V and 2.5 V dual UART, 5 Mbit/s (max.), with 64-byte FIFOs QFP 48-Pin;
SC16C752BIB48,128
型号: SC16C752BIB48,128
厂家: NXP    NXP
描述:

SC16C752B - 5 V, 2.2 V and 2.5 V dual UART, 5 Mbit/s (max.), with 64-byte FIFOs QFP 48-Pin

通信 时钟 数据传输 先进先出芯片 外围集成电路
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SC16C752B  
5 V, 2.2 V and 2.5 V dual UART, 5 Mbit/s (max.), with 64-byte  
FIFOs  
Rev. 6 — 30 November 2010  
Product data sheet  
1. General description  
The SC16C752B is a dual Universal Asynchronous Receiver/Transmitter (UART) with  
64-byte FIFOs, automatic hardware/software flow control, and data rates up to 5 Mbit/s  
(3.3 V and 5 V). The SC16C752B offers enhanced features. It has a Transmission Control  
Register (TCR) that stores receiver FIFO threshold levels to start/stop transmission during  
hardware and software flow control. With the FIFO Rdy register, the software gets the  
status of TXRDYn/RXRDYn for all four ports in one access. On-chip status registers  
provide the user with error indications, operational status, and modem interface control.  
System interrupts may be tailored to meet user requirements. An internal loopback  
capability allows on-board diagnostics.  
The UART transmits data, sent to it over the peripheral 8-bit bus, on the TXn signal and  
receives characters on the RXn signal. Characters can be programmed to be 5 bits, 6 bits,  
7 bits, or 8 bits. The UART has a 64-byte receive FIFO and transmit FIFO and can be  
programmed to interrupt at different trigger levels. The UART generates its own desired  
baud rate based upon a programmable divisor and its input clock. It can transmit even,  
odd, or no parity and 1, 1.5, or 2 stop bits. The receiver can detect break, idle, or framing  
errors, FIFO overflow, and parity errors. The transmitter can detect FIFO underflow. The  
UART also contains a software interface for modem control operations, and has software  
flow control and hardware flow control capabilities.  
The SC16C752B is available in plastic LQFP48 and HVQFN32 packages.  
2. Features and benefits  
„ Pin compatible with SC16C2550 with additional enhancements  
„ Up to 5 Mbit/s baud rate (at 3.3 V and 5 V; at 2.5 V maximum baud rate is 3 Mbit/s)  
„ 64-byte transmit FIFO  
„ 64-byte receive FIFO with error flags  
„ Programmable and selectable transmit and receive FIFO trigger levels for DMA and  
interrupt generation  
„ Software/hardware flow control  
‹ Programmable Xon/Xoff characters  
‹ Programmable auto-RTS and auto-CTS  
„ Optional data flow resume by Xon any character  
„ DMA signalling capability for both received and transmitted data  
„ Supports 5 V, 3.3 V and 2.5 V operation  
 
 
SC16C752B  
NXP Semiconductors  
5 V, 2.2 V and 2.5 V dual UART, 5 Mbit/s (max.), with 64-byte FIFOs  
„ 5 V tolerant on input only pins1  
„ Software selectable baud rate generator  
„ Prescaler provides additional divide-by-4 function  
„ Industrial temperature range (40 °C to +85 °C)  
„ Pin and software compatible with SC16C752, TL16C752  
„ Fast data bus access time  
„ Programmable Sleep mode  
„ Programmable serial interface characteristics  
‹ 5-bit, 6-bit, 7-bit, or 8-bit characters  
‹ Even, odd, or no parity bit generation and detection  
‹ 1, 1.5, or 2 stop bit generation  
„ False start bit detection  
„ Complete status reporting capabilities in both normal and Sleep mode  
„ Line break generation and detection  
„ Internal test and loopback capabilities  
„ Fully prioritized interrupt system controls  
„ Modem control functions (CTS, RTS, DSR, DTR, RI, and CD)  
3. Ordering information  
Table 1.  
Ordering information  
Type number  
Package  
Name  
Description  
Version  
SC16C752BIB48  
SC16C752BIBS  
LQFP48  
HVQFN32  
plastic low profile quad flat package; 48 leads; body 7 × 7 × 1.4 mm  
SOT313-2  
SOT617-1  
plastic thermal enhanced very thin quad flat package; no leads;  
32 terminals; body 5 × 5 × 0.85 mm  
1. For data bus, D7 to D0, see Table 24 “Limiting values”.  
SC16C752B  
All information provided in this document is subject to legal disclaimers.  
© NXP B.V. 2010. All rights reserved.  
Product data sheet  
Rev. 6 — 30 November 2010  
2 of 47  
 
SC16C752B  
NXP Semiconductors  
5 V, 2.2 V and 2.5 V dual UART, 5 Mbit/s (max.), with 64-byte FIFOs  
4. Block diagram  
SC16C752B  
TRANSMIT  
FIFO  
TRANSMIT  
SHIFT  
TXA, TXB  
REGISTERS  
REGISTER  
D0 to D7  
IOR  
DATA BUS  
AND  
IOW  
RESET  
CONTROL  
LOGIC  
FLOW  
CONTROL  
LOGIC  
RECEIVE  
FIFO  
RECEIVE  
SHIFT  
RXA, RXB  
REGISTERS  
REGISTER  
FLOW  
CONTROL  
LOGIC  
A0 to A2  
CSA  
REGISTER  
SELECT  
LOGIC  
CSB  
DTRA, DTRB  
RTSA, RTSB  
OPA, OPB  
MODEM  
CONTROL  
LOGIC  
CTSA, CTSB  
RIA, RIB  
CDA, CDB  
DSRA, DSRB  
INTA, INTB  
TXRDYA, TXRDYB  
RXRDYA, RXRDYB  
CLOCK AND  
BAUD RATE  
GENERATOR  
INTERRUPT  
CONTROL  
LOGIC  
002aaa600  
XTAL1  
XTAL2  
Fig 1. Block diagram  
SC16C752B  
All information provided in this document is subject to legal disclaimers.  
© NXP B.V. 2010. All rights reserved.  
Product data sheet  
Rev. 6 — 30 November 2010  
3 of 47  
 
 
SC16C752B  
NXP Semiconductors  
5 V, 2.2 V and 2.5 V dual UART, 5 Mbit/s (max.), with 64-byte FIFOs  
5. Pinning information  
5.1 Pinning  
1
2
36  
35  
34  
33  
32  
31  
30  
29  
28  
27  
26  
25  
D5  
D6  
RESET  
DTRB  
DTRA  
RTSA  
OPA  
RXRDYA  
INTA  
INTB  
A0  
3
D7  
4
RXB  
RXA  
TXRDYB  
TXA  
5
6
SC16C752BIB48  
7
8
TXB  
9
OPB  
CSA  
CSB  
n.c.  
10  
11  
12  
A1  
A2  
n.c.  
002aaa601  
Fig 2. Pin configuration for LQFP48  
terminal 1  
index area  
1
2
3
4
5
6
7
8
24  
23  
22  
21  
20  
19  
18  
17  
D6  
D7  
RESET  
RTSA  
OPA  
INTA  
INTB  
A0  
RXB  
RXA  
TXA  
TXB  
OPB  
CSA  
SC16C752BIBS  
A1  
A2  
002aaa950  
Transparent top view  
Fig 3. Pin configuration for HVQFN32  
SC16C752B  
All information provided in this document is subject to legal disclaimers.  
© NXP B.V. 2010. All rights reserved.  
Product data sheet  
Rev. 6 — 30 November 2010  
4 of 47  
 
 
SC16C752B  
NXP Semiconductors  
5 V, 2.2 V and 2.5 V dual UART, 5 Mbit/s (max.), with 64-byte FIFOs  
5.2 Pin description  
Table 2.  
Symbol  
Pin description  
Pin  
Type Description  
LQFP48 HVQFN32  
A0  
28  
27  
26  
40  
16  
19  
18  
17  
-
I
I
I
I
i
Address 0 select bit. Internal registers address selection.  
Address 1 select bit. Internal registers address selection.  
Address 2 select bit. Internal registers address selection.  
A1  
A2  
CDA  
CDB  
Carrier Detect (active LOW). These inputs are associated with individual  
UART channels A and B. A logic LOW on these pins indicates that a carrier has  
been detected by the modem for that channel. The state of these inputs is  
reflected in the Modem Status Register (MSR).  
-
CSA  
CSB  
10  
11  
8
9
I
I
Chip Select (active LOW). These pins enable data transfers between the user  
CPU and the SC16C752B for the channel(s) addressed. Individual UART  
sections (A, B) are addressed by providing a logic LOW on the respective CSA  
and CSB pins.  
CTSA  
CTSB  
38  
23  
25  
16  
I
I
Clear to Send (active LOW). These inputs are associated with individual UART  
channels A and B. A logic 0 (LOW) on the CTSn pins indicates the modem or  
data set is ready to accept transmit data from the SC16C752B. Status can be  
tested by reading MSR[4]. These pins only affect the transmit and receive  
operations when auto-CTS function is enabled via the Enhanced Feature  
Register EFR[7] for hardware flow control operation.  
D0  
44  
45  
46  
47  
48  
1
27  
28  
29  
30  
31  
32  
1
I/O  
I/O  
I/O  
I/O  
I/O  
I/O  
I/O  
I/O  
I
Data bus (bidirectional). These pins are the 8-bit, 3-state data bus for  
transferring information to or from the controlling CPU. D0 is the least significant  
bit and the first data bit in a transmit or receive serial data stream.  
D1  
D2  
D3  
D4  
D5  
D6  
2
D7  
3
2
DSRA  
DSRB  
39  
20  
-
Data Set Ready (active LOW). These inputs are associated with individual  
UART channels A and B. A logic 0 (LOW) on these pins indicates the modem or  
data set is powered-on and is ready for data exchange with the UART. The state  
of these inputs is reflected in the Modem Status Register (MSR).  
-
I
DTRA  
DTRB  
34  
35  
-
-
O
O
Data Terminal Ready (active LOW). These outputs are associated with  
individual UART channels A and B. A logic 0 (LOW) on these pins indicates that  
the SC16C752B is powered-on and ready. These pins can be controlled via the  
modem control register. Writing a logic 1 to MCR[0] will set the DTRn output to  
logic 0 (LOW), enabling the modem. The output of these pins will be a logic 1  
after writing a logic 0 to MCR[0], or after a reset.  
GND  
INTA  
INTB  
17  
30  
29  
13  
21  
20  
I
Signal and power ground  
O
O
Interrupt A and B (active HIGH). These pins provide individual channel  
interrupts INTA and INTB. INTA and INTB are enabled when MCR[3] is set to a  
logic 1, interrupt sources are enabled in the Interrupt Enable Register (IER).  
Interrupt conditions include: receiver errors, available receiver buffer data,  
available transmit buffer space, or when a modem status flag is detected. INTA,  
INTB are in the high-impedance state after reset.  
IOR  
19  
14  
I
Input/Output Read strobe (active LOW). A HIGH-to-LOW transition on IOR  
will load the contents of an internal register defined by address bits A0 to A2  
onto the SC16C752B data bus (D0 to D7) for access by external CPU.  
SC16C752B  
All information provided in this document is subject to legal disclaimers.  
© NXP B.V. 2010. All rights reserved.  
Product data sheet  
Rev. 6 — 30 November 2010  
5 of 47  
 
 
SC16C752B  
NXP Semiconductors  
5 V, 2.2 V and 2.5 V dual UART, 5 Mbit/s (max.), with 64-byte FIFOs  
Table 2.  
Symbol  
Pin description …continued  
Pin  
Type Description  
LQFP48 HVQFN32  
IOW  
n.c.  
15  
12  
I
Input/Output Write strobe (active LOW). A LOW-to-HIGH transition on IOW  
will transfer the contents of the data bus (D0 to D7) from the external CPU to an  
internal register that is defined by address bits A0 to A2 and CSA and CSB.  
12, 24,  
25, 37  
-
-
not connected  
OPA  
OPB  
32  
9
22  
7
O
O
User defined outputs. This function is associated with individual channels A  
and B. The state of these pins is defined by the user through the software  
settings of MCR[3]. INTA-INTB are set to active mode and OPA-OPB to a logic 0  
when MCR[3] is set to a logic 1. INTA-INTB are set to the 3-state mode and  
OPA-OPB to a logic 1 when MCR[3] is set to a logic 0. The output of these two  
pins is HIGH after reset.  
RESET  
36  
24  
I
Reset. This pin will reset the internal registers and all the outputs. The UART  
transmitter output and the receiver input will be disabled during reset time.  
RESET is an active HIGH input.  
RIA  
RIB  
41  
21  
-
-
I
I
Ring Indicator (active LOW). These inputs are associated with individual  
UART channels, A and B. A logic 0 on these pins indicates the modem has  
received a ringing signal from the telephone line. A LOW-to-HIGH transition on  
these input pins generates a modem status interrupt, if enabled. The state of  
these inputs is reflected in the Modem Status Register (MSR).  
RTSA  
RTSB  
33  
22  
23  
15  
O
O
Request to Send (active LOW). These outputs are associated with individual  
UART channels, A and B. A logic 0 on the RTSn 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 these pins are set to a logic 1. These pins only affect the transmit and  
receive operations when auto-RTS function is enabled via the Enhanced  
Feature Register (EFR[6]) for hardware flow control operation.  
RXA  
RXB  
5
4
4
3
I
I
Receive data input. These inputs are associated with individual serial channel  
data to the SC16C752B. During the local Loopback mode, these RXn input pins  
are disabled and transmit data is connected to the UART receive input internally.  
RXRDYA 31  
RXRDYB 18  
-
-
O
O
Receive Ready (active LOW). RXRDYA or RXRDYB goes LOW when the  
trigger level has been reached or the FIFO has at least one character. It goes  
HIGH when the receive FIFO is empty.  
TXA  
TXB  
7
8
5
6
O
O
Transmit data A, B. These outputs are associated with individual serial transmit  
channel data from the SC16C752B. During the local Loopback mode, the TXn  
output pin is disabled and transmit data is internally connected to the UART  
receive input.  
TXRDYA  
TXRDYB  
43  
6
-
-
O
O
Transmit Ready (active LOW). TXRDYA or TXRDYB go LOW when there are  
at least a trigger level number of spaces available or when the FIFO is empty. It  
goes HIGH when the FIFO is full or not empty.  
VCC  
42  
13  
26  
10  
I
I
Power supply input  
XTAL1  
Crystal or external clock input. Functions as a crystal input or as an external  
clock input. A crystal can be connected between XTAL1 and XTAL2 to form an  
internal oscillator circuit (see Figure 13). Alternatively, an external clock can be  
connected to this pin to provide custom data rates.  
XTAL2  
14  
11  
O
Output of the crystal oscillator or buffered clock. (See also XTAL1.) XTAL2  
is used as a crystal oscillator output or a buffered clock output.  
SC16C752B  
All information provided in this document is subject to legal disclaimers.  
© NXP B.V. 2010. All rights reserved.  
Product data sheet  
Rev. 6 — 30 November 2010  
6 of 47  
SC16C752B  
NXP Semiconductors  
5 V, 2.2 V and 2.5 V dual UART, 5 Mbit/s (max.), with 64-byte FIFOs  
6. Functional description  
The SC16C752B UART is pin-compatible with the SC16C2550 UART. It provides more  
enhanced features. All additional features are provided through a special Enhanced  
Feature Register (EFR).  
The UART will perform serial-to-parallel conversion on data characters received from  
peripheral devices or modems, and parallel-to-parallel conversion on data characters  
transmitted by the processor. The complete status of each channel of the SC16C752B  
UART can be read at any time during functional operation by the processor.  
The SC16C752B can be placed in an alternate mode (FIFO mode) relieving the processor  
of excessive software overhead by buffering received/transmitted characters. Both the  
receiver and transmitter FIFOs can store up to 64 bytes (including three additional bits of  
error status per byte for the receiver FIFO) and have selectable or programmable trigger  
levels. Primary outputs RXRDYn and TXRDYn allow signalling of DMA transfers.  
The SC16C752B 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 RTSn output and CTSn  
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).  
6.1 Trigger levels  
The SC16C752B provides independent selectable and programmable trigger levels for  
both receiver and transmitter DMA and interrupt generation. After reset, both transmitter  
and receiver FIFOs are disabled and so, in effect, the trigger level is the default value of  
one byte. The selectable trigger levels are available via the FIFO Control Register (FCR).  
The programmable trigger levels are available via the Trigger Level Register (TLR).  
6.2 Hardware flow control  
Hardware flow control is comprised of auto-CTS and auto-RTS. Auto-CTS and auto-RTS  
can be enabled/disabled independently by programming EFR[7:6].  
With auto-CTS, CTSn must be active before the UART can transmit data.  
Auto-RTS only activates the RTSn output when there is enough room in the FIFO to  
receive data and de-activates the RTSn output when the receive FIFO is sufficiently full.  
The halt and resume trigger levels in the TCR determine the levels at which RTSn is  
activated/deactivated.  
If both auto-CTS and auto-RTS are enabled, when RTSn is connected to CTSn, 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.  
SC16C752B  
All information provided in this document is subject to legal disclaimers.  
© NXP B.V. 2010. All rights reserved.  
Product data sheet  
Rev. 6 — 30 November 2010  
7 of 47  
 
 
 
SC16C752B  
NXP Semiconductors  
5 V, 2.2 V and 2.5 V dual UART, 5 Mbit/s (max.), with 64-byte FIFOs  
UART 1  
UART 2  
SERIAL TO  
PARALLEL  
PARALLEL  
TO SERIAL  
RXn  
TXn  
RX  
TX  
FIFO  
FIFO  
RTSn  
CTSn  
FLOW  
FLOW  
CONTROL  
CONTROL  
D7 to D0  
D7 to D0  
PARALLEL  
TO SERIAL  
SERIAL TO  
PARALLEL  
TXn  
RXn  
TX  
RX  
FIFO  
FIFO  
CTSn  
RTSn  
FLOW  
FLOW  
CONTROL  
CONTROL  
002aaf905  
Fig 4. Auto flow control (auto-RTS and auto-CTS) example  
6.2.1 Auto-RTS  
Auto-RTS data flow control originates in the receiver block (see Figure 1 “Block diagram”  
on page 3). Figure 5 shows RTSn functional timing. The receiver FIFO trigger levels used  
in auto-RTS are stored in the TCR. RTSn 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, RTSn is  
de-asserted. The sending device (e.g., another UART) may send an additional byte after  
the trigger level is reached (assuming the sending UART has another byte to send)  
because it may not recognize the de-assertion of RTSn until it has begun sending the  
additional byte. RTSn 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.  
RXn  
Start  
byte N  
Stop  
Start  
byte N + 1  
Stop  
Start  
RTSn  
1
2
N
N+1  
IOR  
002aaf906  
N = receiver FIFO trigger level.  
The two blocks in dashed lines cover the case where an additional byte is sent, as described in Section 6.2.1.  
Fig 5. RTS functional timing  
SC16C752B  
All information provided in this document is subject to legal disclaimers.  
© NXP B.V. 2010. All rights reserved.  
Product data sheet  
Rev. 6 — 30 November 2010  
8 of 47  
 
 
SC16C752B  
NXP Semiconductors  
5 V, 2.2 V and 2.5 V dual UART, 5 Mbit/s (max.), with 64-byte FIFOs  
6.2.2 Auto-CTS  
The transmitter circuitry checks CTSn before sending the next data byte. When CTSn is  
active, the transmitter sends the next byte. To stop the transmitter from sending the  
following byte, CTSn 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, CTSn 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.  
Start  
byte 0 to 7  
Stop  
TXn  
Start  
byte 0 to 7  
Stop  
CTSn  
002aaa227  
When CTSn is LOW, the transmitter keeps sending serial data out.  
When CTSn goes HIGH before the middle of the last stop bit of the current byte, the transmitter finishes sending the current  
byte, but is does not send the next byte.  
When CTSn goes from HIGH to LOW, the transmitter begins sending data again.  
Fig 6. CTS functional timing  
6.3 Software flow control  
Software flow control is enabled through the enhanced feature register and the modem  
control register. Different combinations of software flow control can be enabled by setting  
different combinations of EFR[3:0]. Table 3 shows software flow control options.  
Table 3.  
Software flow control options (EFR[0:3])  
EFR[3]  
EFR[2]  
EFR[1]  
EFR[0]  
TX, RX software flow controls  
no transmit flow control  
0
1
0
1
X
X
X
1
0
0
1
1
X
X
X
0
X
X
X
X
0
1
0
1
X
X
X
X
0
0
1
1
transmit Xon1, Xoff1  
transmit Xon2, Xoff2  
transmit Xon1, Xon2, Xoff1, Xoff2  
no receive flow control  
receiver compared Xon1, Xoff1  
receiver compares Xon2, Xoff2  
transmit Xon1, Xoff1  
receiver compares Xon1 and Xon2, Xoff1 and Xoff2  
transmit Xon2, Xoff2  
0
1
1
1
1
1
1
1
receiver compares Xon1 and Xon2, Xoff1 and Xoff2  
transmit Xon1, Xon2, Xoff1, Xoff2  
receiver compares Xon1 and Xon2, Xoff1 and Xoff2  
SC16C752B  
All information provided in this document is subject to legal disclaimers.  
© NXP B.V. 2010. All rights reserved.  
Product data sheet  
Rev. 6 — 30 November 2010  
9 of 47  
 
 
 
SC16C752B  
NXP Semiconductors  
5 V, 2.2 V and 2.5 V dual UART, 5 Mbit/s (max.), with 64-byte FIFOs  
There are two other enhanced features relating to software flow control:  
Xon Any function (MCR[5]): Operation will resume after receiving any character  
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 receive FIFO.  
Special character (EFR[5]): Incoming data is compared to Xoff2. Detection of the  
special character sets the Xoff interrupt (IIR[4]) but does not halt transmission. The  
Xoff interrupt is cleared by a read of the IIR. The special character is transferred to the  
receive FIFO.  
6.3.1 Receive flow control  
When software flow control operation is enabled, the SC16C752B will compare incoming  
data with Xoff1/Xoff2 programmed characters (in certain cases, Xoff1 and Xoff2 must be  
received sequentially). When the correct Xoff character 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 INTA/INTB to go HIGH.  
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.  
6.3.2 Transmit flow control  
Xoff1/Xoff2 character is transmitted when the receive FIFO has passed the halt trigger  
level programmed in TCR[3:0].  
Xon1/Xon2 character is transmitted when the receive FIFO reaches the resume trigger  
level programmed in TCR[7:4].  
The transmission of Xoff/Xon(s) follows the exact same protocol as transmission of an  
ordinary byte from the FIFO. This means that even if the word length is set to be 5, 6, or 7  
characters, then the 5, 6, or 7 least significant bits of Xoff1/Xoff2, Xon1/Xoff2 will be  
transmitted. (Note that the transmission of 5 bits, 6 bits, 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.  
SC16C752B  
All information provided in this document is subject to legal disclaimers.  
© NXP B.V. 2010. All rights reserved.  
Product data sheet  
Rev. 6 — 30 November 2010  
10 of 47  
 
 
SC16C752B  
NXP Semiconductors  
5 V, 2.2 V and 2.5 V dual UART, 5 Mbit/s (max.), with 64-byte FIFOs  
6.3.3 Software flow control example  
UART1  
UART2  
TRANSMIT FIFO  
RECEIVE FIFO  
data  
PARALLEL-TO-SERIAL  
SERIAL-TO-PARALLEL  
Xon1 WORD  
SERIAL-TO-PARALLEL  
PARALLEL-TO-SERIAL  
Xon1 WORD  
Xoff–Xon–Xoff  
Xon2 WORD  
Xon2 WORD  
Xoff1 WORD  
Xoff1 WORD  
compare  
programmed  
Xon-Xoff  
Xoff2 WORD  
Xoff2 WORD  
characters  
002aaa229  
Fig 7. Software flow control example  
6.3.3.1 Assumptions  
UART1 is transmitting a large text file to UART2. Both UARTs are using software flow  
control with single character Xoff (0Fh) and Xon (0Dh) tokens. Both have Xoff threshold  
(TCR[3:0] = Fh) set to 60, and Xon threshold (TCR[7:4] = 8h) set to 32. Both have the  
interrupt receive threshold (TLR[7:4] = Dh) set to 52.  
UART 1 begins transmission and sends 52 characters, at which point UART2 will  
generate an interrupt to its processor to service the receive FIFO, but assume the  
interrupt latency is fairly long. UART1 will continue sending characters until a total of 60  
characters have been sent. At this time, UART2 will transmit a 0Fh to UART1, informing  
UART1 to halt transmission. UART1 will likely send the 61st character while UART2 is  
sending the Xoff character. Now UART2 is serviced and the processor reads enough data  
out of the receive FIFO that the level drops to 32. UART2 will now send a 0Dh to UART1,  
informing UART1 to resume transmission.  
SC16C752B  
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Product data sheet  
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SC16C752B  
NXP Semiconductors  
6.4 Reset  
5 V, 2.2 V and 2.5 V dual UART, 5 Mbit/s (max.), with 64-byte FIFOs  
Table 4 summarizes the state of register after reset.  
Table 4.  
Register  
Register reset functions[1]  
Reset control  
RESET  
RESET  
RESET  
RESET  
RESET  
RESET  
RESET  
RESET  
RESET  
RESET  
RESET  
RESET  
Reset state  
Interrupt Enable Register  
Interrupt Identification Register  
FIFO Control Register  
all bits cleared  
bit 0 is set; all other bits cleared  
all bits cleared  
Line Control Register  
reset to 0001 1101 (1Dh)  
all bits cleared  
Modem Control Register  
Line Status Register  
bit 5 and bit 6 set; all other bits cleared  
bits [3:0] cleared; bits [7:4] input signals  
all bits cleared  
Modem Status Register  
Enhanced Feature Register  
Receiver Holding Register  
Transmitter Holding Register  
Transmission Control Register  
Trigger Level Register  
pointer logic cleared  
pointer logic cleared  
all bits cleared  
all bits cleared  
[1] Registers DLL, DLM, SPR, XON1, XON2, XOFF1, XOFF2 are not reset by the top-level reset signal  
RESET, i.e., they hold their initialization values during reset.  
Table 5 summarizes the state of registers after reset.  
Table 5.  
Signal  
TXn  
Signal RESET functions  
Reset control  
Reset state  
HIGH  
RESET  
RESET  
RESET  
RESET  
RESET  
RTSn  
HIGH  
DTRn  
HIGH  
RXRDYn  
TXRDYn  
HIGH  
LOW  
SC16C752B  
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Product data sheet  
Rev. 6 — 30 November 2010  
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SC16C752B  
NXP Semiconductors  
5 V, 2.2 V and 2.5 V dual UART, 5 Mbit/s (max.), with 64-byte FIFOs  
6.5 Interrupts  
The SC16C752B has interrupt generation and prioritization (six prioritized levels of  
interrupts) capability. The Interrupt Enable Register (IER) enables each of the six types of  
interrupts and the INTA/INTB signal in response to an interrupt generation. The IER can  
also disable the interrupt system by clearing bit 0 to bit 3 and bit 5 to bit 7. 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.  
IIR[5:0]  
Interrupt control functions  
Priority  
level  
Interrupt type  
Interrupt source  
Interrupt reset method  
00 0001  
00 0110  
None  
1
none  
none  
none  
receiver line status  
OE, FE, PE, or BI errors occur in  
characters in the RX FIFO  
FE, PE, BI: all erroneous  
characters are read from the  
RX FIFO.  
OE: read LSR  
read RHR  
00 1100  
00 0100  
2
2
RX time-out  
stale data in RX FIFO  
DRDY (data ready)  
(FIFO disable)  
RHR interrupt  
read RHR  
RX FIFO above trigger level  
(FIFO enable)  
00 0010  
3
THR interrupt  
TFE (THR empty)  
read IIR or a write to the THR  
(FIFO disable)  
TX FIFO passes above trigger level  
(FIFO enable)  
00 0000  
01 0000  
4
5
modem status  
Xoff interrupt  
MSR[3:0] = logic 0  
read MSR  
receive Xoff character(s)/special  
character  
receive Xon character(s)/Read of  
IIR  
10 0000  
6
CTS, RTS  
RTSn pin or CTSn pin change state  
from active (LOW) to inactive (HIGH)  
read IIR  
It is important to note that for the framing error, parity error, and break conditions, LSR[7]  
generates the interrupt. LSR[7] is set when there is an error anywhere in the RX FIFO,  
and is cleared only when there are no more errors remaining in the FIFO. LSR[4:2] always  
represent the error status for the received character at the top of the RX FIFO. Reading  
the RX FIFO updates LSR[4:2] to the appropriate status for the new character at the top of  
the FIFO. If the RX FIFO is empty, then LSR[4:2] are all zeros.  
For the Xoff interrupt, if an Xoff flow character detection caused the interrupt, the interrupt  
is cleared by an Xon flow character detection. If a special character detection caused the  
interrupt, the interrupt is cleared by a read of the LSR.  
SC16C752B  
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© NXP B.V. 2010. All rights reserved.  
Product data sheet  
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SC16C752B  
NXP Semiconductors  
5 V, 2.2 V and 2.5 V dual UART, 5 Mbit/s (max.), with 64-byte FIFOs  
6.5.1 Interrupt mode operation  
In interrupt mode (if any bit of IER[3:0] is 1) the processor is informed of the status of the  
receiver and transmitter by an interrupt signal, INTA/INTB. 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  
IOW / IOR  
INTn  
PROCESSOR  
IER  
1
1
1
1
THR  
RHR  
002aaf908  
Fig 8. Interrupt mode operation  
6.5.2 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  
IOW / IOR  
PROCESSOR  
IER  
0
0
0
0
THR  
RHR  
002aaa231  
Fig 9. FIFO polled mode operation  
SC16C752B  
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Product data sheet  
Rev. 6 — 30 November 2010  
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SC16C752B  
NXP Semiconductors  
5 V, 2.2 V and 2.5 V dual UART, 5 Mbit/s (max.), with 64-byte FIFOs  
6.6 DMA operation  
There are two modes of DMA operation, DMA mode 0 or DMA mode 1, selected by  
FCR[3].  
In DMA mode 0 or FIFO disable (FCR[0] = 0) DMA occurs in single character transfers. In  
DMA mode 1, multi-character (or block) DMA transfers are managed to relieve the  
processor for longer periods of time.  
6.6.1 Single DMA transfers (DMA mode 0/FIFO disable)  
Figure 10 shows TXRDYn and RXRDYn in DMA mode 0/FIFO disable.  
transmit  
receive  
TXRDYn  
RXRDYn  
at least one  
at least one  
wrptr  
rdptr  
location filled  
location filled  
TXRDYn  
RXRDYn  
FIFO EMPTY  
FIFO EMPTY  
wrptr  
rdptr  
002aaa232  
Fig 10. TXRDYn and RXRDYn in DMA mode 0/FIFO disable  
6.6.1.1 Transmitter  
When empty, the TXRDYn signal becomes active. TXRDYn will go inactive after one  
character has been loaded into it.  
6.6.1.2 Receiver  
RXRDYn is active when there is at least one character in the FIFO. It becomes inactive  
when the receiver is empty.  
SC16C752B  
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© NXP B.V. 2010. All rights reserved.  
Product data sheet  
Rev. 6 — 30 November 2010  
15 of 47  
 
 
 
 
 
SC16C752B  
NXP Semiconductors  
5 V, 2.2 V and 2.5 V dual UART, 5 Mbit/s (max.), with 64-byte FIFOs  
6.6.2 Block DMA transfers (DMA mode 1)  
Figure 11 shows TXRDYn and RXRDYn in DMA mode 1.  
transmit  
receive  
wrptr  
trigger  
level  
TXRDYn  
rdptr  
RXRDYn  
at least one  
FIFO full  
location filled  
trigger  
level  
TXRDYn  
wrptr  
RXRDYn  
FIFO EMPTY  
rdptr  
002aaa234  
Fig 11. TXRDYn and RXRDYn in DMA mode 1  
6.6.2.1 Transmitter  
TXRDYn is active when there is a trigger level number of spaces available. It becomes  
inactive when the FIFO is full.  
6.6.2.2 Receiver  
RXRDYn becomes active when the trigger level has been reached, or when a time-out  
interrupt occurs. It will go inactive when the FIFO is empty or an error in the receive FIFO  
is flagged by LSR[7].  
6.7 Sleep mode  
Sleep mode is an enhanced feature of the SC16C752B 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, RXn, is idle (see Section 6.8 “Break and time-out  
conditions”).  
The transmit FIFO and transmit shift register are empty.  
There are no interrupts pending except THR and time-out interrupts.  
Remark: Sleep mode will not be entered if there is data in the receive FIFO.  
In Sleep mode, the UART clock and baud rate clock are 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 RXn line, when there is any change in the  
state of the modem input pins, or if data is written to the transmit FIFO.  
Remark: Writing to the divisor latches DLL and DLM 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 DLM.  
SC16C752B  
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© NXP B.V. 2010. All rights reserved.  
Product data sheet  
Rev. 6 — 30 November 2010  
16 of 47  
 
 
 
 
 
SC16C752B  
NXP Semiconductors  
5 V, 2.2 V and 2.5 V dual UART, 5 Mbit/s (max.), with 64-byte FIFOs  
6.8 Break and time-out conditions  
An RX idle condition is detected when the receiver line, RXn, has been HIGH for  
4 character time. The receiver line is sampled midway through each bit.  
When a break condition occurs, the TXn line is pulled LOW. A break condition is activated  
by setting LCR[6].  
6.9 Programmable baud rate generator  
The SC16C752B UART contains a programmable baud 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 12. The output frequency of the baud rate generator is 16 × the baud rate. The  
formula for the divisor is given in Equation 1:  
XTAL1 crystal input frequency  
-----------------------------------------------------------------------------------  
prescaler  
divisor =  
(1)  
----------------------------------------------------------------------------------------  
(desired baud rate × 16)  
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.  
Figure 12 shows the internal prescaler and baud rate generator circuitry.  
PRESCALER  
MCR[7] = 0  
LOGIC  
(DIVIDE-BY-1)  
internal  
XTAL1  
INTERNAL  
OSCILLATOR  
LOGIC  
BAUD RATE  
GENERATOR  
LOGIC  
baud rate  
clock for  
transmitter  
and receiver  
input clock  
XTAL2  
reference  
clock  
PRESCALER  
LOGIC  
(DIVIDE-BY-4)  
MCR[7] = 1  
002aaa233  
Fig 12. Prescaler and baud rate generator block diagram  
DLL and DLM must be written to in order to program the baud rate. DLL and DLM are the  
least significant and most significant byte of the baud rate divisor. If DLL and DLM 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 13 shows the crystal clock circuit reference.  
SC16C752B  
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© NXP B.V. 2010. All rights reserved.  
Product data sheet  
Rev. 6 — 30 November 2010  
17 of 47  
 
 
 
 
SC16C752B  
NXP Semiconductors  
5 V, 2.2 V and 2.5 V dual UART, 5 Mbit/s (max.), with 64-byte FIFOs  
Table 7.  
Baud rates using a 1.8432 MHz crystal  
Desired baud rate  
Divisor used to generate  
Percent error difference  
16× clock  
between desired and actual  
50  
2304  
1536  
1047  
857  
768  
384  
192  
96  
75  
110  
0.026  
0.058  
134.5  
150  
300  
600  
1200  
1800  
2000  
2400  
3600  
4800  
7200  
9600  
19200  
38400  
56000  
64  
58  
0.69  
48  
32  
24  
16  
12  
6
3
2
2.86  
Table 8.  
Baud rates using a 3.072 MHz crystal  
Desired baud rate  
Divisor used to generate  
Percent error difference  
16× clock  
between desired and actual  
50  
2304  
2560  
1745  
1428  
1280  
640  
320  
160  
107  
96  
75  
110  
0.026  
0.034  
134.5  
150  
300  
600  
1200  
1800  
2000  
2400  
3600  
4800  
7200  
9600  
19200  
38400  
0.312  
80  
53  
0.628  
1.23  
40  
27  
20  
10  
5
SC16C752B  
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© NXP B.V. 2010. All rights reserved.  
Product data sheet  
Rev. 6 — 30 November 2010  
18 of 47  
SC16C752B  
NXP Semiconductors  
5 V, 2.2 V and 2.5 V dual UART, 5 Mbit/s (max.), with 64-byte FIFOs  
XTAL1  
XTAL2  
XTAL1  
XTAL2  
1.5 kΩ  
X1  
X1  
1.8432 MHz  
1.8432 MHz  
C1  
22 pF  
C2  
33 pF  
C1  
22 pF  
C2  
47 pF  
002aaa870  
Fig 13. Crystal oscillator connections  
7. Register descriptions  
Each register is selected using address lines A0, A1, A2, and in some cases, bits from  
other registers. The programming combinations for register selection are shown in  
Table 9.  
Table 9.  
A1  
Register map - read/write properties  
A2  
0
0
0
0
1
1
1
1
0
0
0
1
1
1
1
1
1
1
A0  
0
1
0
1
0
1
0
1
0
1
0
0
1
0
1
0
1
1
Read mode  
Write mode  
0
0
1
1
0
0
1
1
0
0
1
0
0
1
1
1
1
1
Receive Holding Register (RHR)  
Interrupt Enable Register (IER)  
Interrupt Identification Register (IIR)  
Line Control Register (LCR)  
Modem Control Register (MCR)[1]  
Line Status Register (LSR)  
Modem Status Register (MSR)  
Scratchpad Register (SPR)  
Divisor Latch LSB (DLL)[2][3]  
Divisor Latch MSB (DLM)[2][3]  
Enhanced Feature Register (EFR)[2][4]  
Xon1 word[2][4]  
Transmit Holding Register (THR)  
Interrupt Enable Register  
FIFO Control Register (FCR)  
Line Control Register  
Modem Control Register[1]  
Scratchpad Register  
Divisor Latch LSB[2][3]  
Divisor Latch MSB[2][3]  
Enhanced Feature Register[2][4]  
Xon1 word[2][4]  
Xon2 word[2][4]  
Xoff1 word[2][4]  
Xoff2 word[2][4]  
Xon2 word[2][4]  
Xoff1 word[2][4]  
Xoff2 word[2][4]  
Transmission Control Register (TCR)[2][5] Transmission Control Register[2][5]  
Trigger Level Register (TLR)[2][5]  
FIFO ready register[2][6]  
Trigger Level Register[2][5]  
[1] MCR[7] can only be modified when EFR[4] is set.  
[2] Accessed by a combination of address pins and register bits.  
[3] Accessible only when LCR[7] is logic 1.  
[4] Accessible only when LCR is set to 1011 1111 (BFh).  
[5] Accessible only when EFR[4] = logic 1 and MCR[6] = logic 1, i.e., EFR[4] and MCR[6] are read/write  
enables.  
[6] Accessible only when CSA or CSB = logic 0, MCR[2] = logic 1, and loopback is disabled  
(MCR[4] = logic 0).  
SC16C752B  
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© NXP B.V. 2010. All rights reserved.  
Product data sheet  
Rev. 6 — 30 November 2010  
19 of 47  
 
 
 
 
 
 
 
 
SC16C752B  
NXP Semiconductors  
5 V, 2.2 V and 2.5 V dual UART, 5 Mbit/s (max.), with 64-byte FIFOs  
Table 10 lists and describes the SC16C752B internal registers.  
Table 10. SC16C752B internal registers  
Read/  
Write  
A2 A1 A0 Register Bit 7  
General register set[1]  
Bit 6  
Bit 5  
Bit 4  
Bit 3  
Bit 2  
Bit 1  
Bit 0  
0
0
0
0
0
0
0
0
1
RHR  
THR  
IER  
bit 7  
bit 6  
bit 5  
bit 4  
bit 4  
bit 3  
bit 3  
bit 2  
bit 2  
bit 1  
bit 1  
THR  
bit 0  
bit 0  
R
bit 7  
bit 6  
bit 5  
0/Xoff[2]  
W
0/CTS  
interrupt interrupt  
enable[2] enable[2]  
0/RTS  
0/X sleep modem receive  
mode[2]  
Rx data R/W  
available  
status  
interrupt interrupt  
line status empty  
interrupt interrupt  
TX FIFO RX FIFO FIFO  
reset reset enable  
0
1
0
FCR  
RXtrigger RX trigger 0/TX  
level  
(MSB)  
0/TX  
DMA  
mode  
select  
W
level (LSB) trigger  
level  
trigger  
level  
(LSB)[2]  
(MSB)[2]  
0
0
1
1
1
1
0
0
0
1
0
1
IIR  
FCR[0]  
DLAB  
FCR[0]  
0/CTS,  
RTS  
0/Xoff  
interrupt interrupt  
priority priority  
interrupt interrupt  
R
priority  
bit 0  
status  
bit 2  
bit 1  
LCR  
MCR  
LSR  
break  
control bit  
set parity parity type parity  
number of word  
enable stop bits length  
word  
length  
bit 0  
R/W  
R/W  
R
select  
bit 1  
1× or  
TCR and  
TLR  
enable[2]  
0/Xon  
Any[2]  
0/enable  
loopback enable ready  
OP enable  
IRQ  
FIFO  
RTS  
DTR  
1× / 4  
clock[2]  
0/error in THR and  
RX FIFO TSR empty empty  
THR  
break  
interrupt  
framing parity  
overrun  
error  
data in  
receiver  
error  
ΔCD  
bit 3  
bit 3  
bit 3  
0
error  
ΔRI  
bit 2  
bit 2  
bit 2  
0
1
1
1
1
1
1
1
1
1
1
0
1
0
1
1
MSR  
SPR  
TCR  
TLR  
CD  
bit 7  
bit 7  
bit 7  
0
RI  
DSR  
bit 5  
bit 5  
bit 5  
CTS  
bit 4  
bit 4  
bit 4  
ΔDSR  
bit 1  
ΔCTS  
bit 0  
bit 0  
bit 0  
R
bit 6  
bit 6  
bit 6  
0
R/W  
R/W  
R/W  
bit 1  
bit 1  
FIFO  
Rdy  
RX FIFO RX FIFO  
B status  
TX FIFO TX FIFO R  
B status A status  
A status  
Special register set[3]  
0
0
0
DLL  
bit 7  
bit 6  
bit 5  
bit 4  
bit 3  
bit 2  
bit 1  
bit 9  
bit 0  
bit 8  
R/W  
R/W  
0
0
1
DLM  
bit 15  
bit 14  
bit 13  
bit 12  
bit 11  
bit 10  
Enhanced register set[4]  
0
1
0
EFR  
auto CTS auto RTS  
Special  
Enable  
software software software software R/W  
character IER[7:4],  
flow  
flow  
flow  
flow  
detect  
FCR[5:4], control control  
control  
bit 1  
control  
bit 0  
MCR[7:5] bit 3  
bit 2  
bit 2  
bit 2  
bit 2  
bit 2  
1
1
1
1
0
0
1
1
0
1
0
1
Xon1  
Xon2  
Xoff1  
Xoff2  
bit 7  
bit 7  
bit 7  
bit 7  
bit 6  
bit 6  
bit 6  
bit 6  
bit 5  
bit 5  
bit 5  
bit 5  
bit 4  
bit 4  
bit 4  
bit 4  
bit 3  
bit 3  
bit 3  
bit 3  
bit 1  
bit 1  
bit 1  
bit 1  
bit 0  
bit 0  
bit 0  
bit 0  
R/W  
R/W  
R/W  
R/W  
[1] These registers are accessible only when LCR[7] = logic 0.  
[2] These bits can only be modified if register bit EFR[4] is enabled, i.e., if enhanced functions are enabled.  
[3] The Special register set is accessible only when LCR[7] is set to a logic 1.  
[4] Enhanced Feature Register; Xon1/Xon2 and Xoff1/Xoff2 are accessible only when LCR is set to BFh.  
SC16C752B  
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© NXP B.V. 2010. All rights reserved.  
Product data sheet  
Rev. 6 — 30 November 2010  
20 of 47  
 
 
 
 
 
SC16C752B  
NXP Semiconductors  
5 V, 2.2 V and 2.5 V dual UART, 5 Mbit/s (max.), with 64-byte FIFOs  
Remark: Refer to the notes under Table 9 for more register access information.  
7.1 Receiver Holding Register (RHR)  
The receiver section consists of the Receiver Holding Register (RHR) and the Receiver  
Shift Register (RSR). The RHR is actually a 64-byte FIFO. The RSR receives serial data  
from the RX 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.  
Remark: In this case, characters are overwritten if overflow occurs.  
If overflow occurs, characters are lost. The RHR also stores the error status bits  
associated with each character.  
7.2 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 TXn  
terminal. If the FIFO is disabled, the FIFO is still used to store the byte. Characters are  
lost if overflow occurs.  
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5 V, 2.2 V and 2.5 V dual UART, 5 Mbit/s (max.), with 64-byte FIFOs  
7.3 FIFO Control Register (FCR)  
This is a write-only register that is used for enabling the FIFOs, clearing the FIFOs, setting  
transmitter and receiver trigger levels, and selecting the type of DMA signalling. Table 11  
shows FIFO control register bit settings.  
Table 11. FIFO Control Register bits description  
Bit  
Symbol  
Description  
7:6  
FCR[7](MSB), RX trigger. Sets the trigger level for the receive FIFO.  
FCR[6] (LSB)  
00 - 8 characters  
01 - 16 characters  
10 - 56 characters  
11 - 60 characters  
5:4  
FCR[5](MSB), TX trigger. Sets the trigger level for the transmit FIFO.  
FCR[4] (LSB)  
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
2
FCR[3]  
FCR[2]  
DMA mode select.  
logic 0 = set DMA mode ‘0’  
logic 1 = set DMA mode ‘1’  
Reset transmit FIFO.  
logic 0 = no FIFO transmit reset (normal default condition)  
logic 1 = Clears the contents of the transmit FIFO and resets the FIFO  
counter logic (the transmit shift register is not cleared or altered). This bit  
will return to a logic 0 after clearing the FIFO.  
1
0
FCR[1]  
FCR[0]  
Reset receive FIFO.  
logic 0 = no FIFO receive reset (normal default condition)  
logic 1 = Clears the contents of the receive FIFO and resets the FIFO  
counter logic (the receive shift register is not cleared or altered). This bit  
will return to a logic 0 after clearing the FIFO.  
FIFO enable.  
logic 0 = disable the transmit and receive FIFO (normal default  
condition)  
logic 1 = enable the transmit and receive FIFO.  
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5 V, 2.2 V and 2.5 V dual UART, 5 Mbit/s (max.), with 64-byte FIFOs  
7.4 Line Control Register (LCR)  
This register controls the data communication format. The word length, number of stop  
bits, and parity type are selected by writing the appropriate bits to the LCR. Table 12  
shows the Line Control Register bit settings.  
Table 12. Line Control Register bits description  
Bit  
Symbol  
Description  
7
LCR[7]  
Divisor latch enable.  
logic 0 = divisor latch disabled (normal default condition)  
logic 1 = divisor latch enabled  
6
5
LCR[6]  
LCR[5]  
Break control bit. When enabled, the Break control bit causes a break  
condition to be transmitted (the TXn output is forced to a logic 0 state). This  
condition exists until disabled by setting LCR[6] to a logic 0.  
logic 0 = no break condition (normal default condition)  
logic 1 = forces the transmitter output (TXn) to a logic 0 to alert the  
communication terminal to a line break condition  
Set parity. LCR[5] selects the forced parity format (if LCR[3] = 1).  
logic 0 = parity is not forced (normal default condition)  
LCR[5] = logic 1 and LCR[4] = logic 0: parity bit is forced to a logic 1 for the  
transmit and receive data.  
LCR[5] = logic 1 and LCR[4] = logic 1: parity bit is forced to a logic 0 for the  
transmit and receive data.  
4
3
LCR[4]  
LCR[3]  
Parity type select.  
logic 0 = odd parity is generated (if LCR[3] = 1)  
logic 1 = even parity is generated (if LCR[3] = 1)  
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 - 1 stop bit (word length = 5, 6, 7, 8)  
1 - 1.5 stop bits (word length = 5)  
1 - 2 stop bits (word length = 6, 7, 8)  
1:0  
LCR[1:0]  
Word length bits 1, 0. These two bits specify the word length to be  
transmitted or received.  
00 - 5 bits  
01 - 6 bits  
10 - 7 bits  
11 - 8 bits  
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7.5 Line Status Register (LSR)  
Table 13 shows the Line Status Register bit settings.  
Table 13. 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
5
LSR[6]  
LSR[5]  
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  
THR empty. This bit is the Transmit Holding Register Empty indicator.  
logic 0 = Transmit Holding Register is not empty  
logic 1 = Transmit Holding Register is empty. The processor can now load  
up to 64 bytes of data into the THR if the transmit FIFO is enabled.  
4
3
LSR[4]  
LSR[3]  
Break interrupt.  
logic 0 = No break condition (normal default condition)  
logic 1 = A break condition occurred and associated byte is 00, i.e.,  
RXn was LOW for one character time frame  
Framing error.  
logic 0 = no framing error in data being read from receive FIFO (normal  
default condition)  
logic 1 = framing error occurred in data being read from receive FIFO, i.e.,  
received data did not have a valid stop bit.  
2
1
0
LSR[2]  
LSR[1]  
LSR[0]  
Parity error.  
logic 0 = no parity error (normal default condition)  
logic 1 = parity error in data being read from receive FIFO  
Overrun error.  
logic 0 = no overrun error (normal default condition)  
logic 1 = overrun error has occurred  
Data in receiver.  
logic 0 = no data in receive FIFO (normal default condition)  
logic 1 = at least one character in the receive FIFO  
When the LSR is read, LSR[4:2] reflect the error bits (BI, FE, PE) of the character at the  
top of the receive FIFO (next character to be read). The LSR[4:2] registers do not  
physically exist, as the data read from the receive FIFO is output directly onto the output  
data bus, DI[4:2], when the LSR is 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 receive FIFO, and is cleared only  
when there are no more errors remaining in the FIFO.  
Reading the LSR does not cause an increment of the receive FIFO read pointer. The  
receive FIFO read pointer is incremented by reading the RHR.  
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5 V, 2.2 V and 2.5 V dual UART, 5 Mbit/s (max.), with 64-byte FIFOs  
7.6 Modem Control Register (MCR)  
The MCR controls the interface with the mode, data set, or peripheral device that is  
emulating the modem. Table 14 shows modem control register bit settings.  
Table 14. Modem Control Register bits description  
Bit  
Symbol  
MCR[7][1] Clock select.  
logic 0 = divide-by-1 clock input  
logic 1 = divide-by-4 clock input  
MCR[6][1] TCR and TLR enable.  
Description  
7
6
5
4
logic 0 = no action  
logic 1 = enable access to the TCR and TLR registers  
MCR[5][1] Xon Any.  
logic 0 = disable Xon Any function  
logic 1 = enable Xon Any function  
Enable loopback.  
MCR[4]  
MCR[3]  
logic 0 = normal operating mode.  
logic 1 = enable local Loopback mode (internal). In this mode the MCR[3:0]  
signals are looped back into MSR[7:4] and the TXn output is looped back to  
the RXn input internally.  
3
IRQ enable OP.  
logic 0 = forces INTA, INTB outputs to the 3-state mode and OP output to  
HIGH state  
logic 1 = forces the INTA-INTB outputs to the active state and OP output to  
LOW state. In Loopback mode, controls MSR[7].  
2
1
MCR[2]  
MCR[1]  
FIFO Ready enable.  
logic 0 = disable the FIFO Rdy register  
logic 1 = enable the FIFO Rdy register. In Loopback mode, controls MSR[6].  
RTS  
logic 0 = force RTSn output to inactive (HIGH)  
logic 1 = force RTSn output to active (LOW). In loopback mode, controls  
MSR[4]. If auto-RTS is enabled, the RTSn output is controlled by hardware  
flow control.  
0
MCR[0]  
DTR  
logic 0 = force DTRn output to inactive (HIGH)  
logic 1 = force DTRn output to active (LOW). In Loopback mode, controls  
MSR[5].  
[1] MCR[7:5] can only be modified when EFR[4] is set, i.e., EFR[4] is a write enable.  
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5 V, 2.2 V and 2.5 V dual UART, 5 Mbit/s (max.), with 64-byte FIFOs  
7.7 Modem Status Register (MSR)  
This 8-bit register provides information about the current state of the control lines from the  
mode, data set, or peripheral device to the processor. It also indicates when a control  
input from the modem changes state. Table 15 shows Modem Status Register bit settings  
per channel.  
Table 15. Modem Status Register bits description  
Bit  
Symbol  
Description  
7
MSR[7]  
CD (active HIGH, logic 1)[1]. This bit is the complement of the CDn input  
during normal mode. During internal Loopback mode, it is equivalent to  
MCR[3].  
6
5
4
MSR[6]  
MSR[5]  
MSR[4]  
RI (active HIGH, logic 1)[1]. This bit is the complement of the RIn input during  
normal mode. During internal Loopback mode, it is equivalent to MCR[2].  
DSR (active HIGH, logic 1)[1]. This bit is the complement of the DSRn input  
during normal mode. During Internal Loopback mode, it is equivalent MCR[0].  
CTS (active HIGH, logic 1)[1]. This bit is the complement of the CTSn input  
during normal mode. During internal Loopback mode, it is equivalent to  
MCR[1].  
3
2
1
0
MSR[3]  
MSR[2]  
MSR[1]  
MSR[0]  
ΔCD. Indicates that CDn input (or MCR[3] in Loopback mode) has changed  
state. Cleared on a read.  
ΔRI. Indicates that RIn input (or MCR[2] in Loopback mode) has changed  
state from LOW to HIGH. Cleared on a read.  
ΔDSR. Indicates that DSRn input (or MCR[0] in Loopback mode) has changed  
state. Cleared on a read.  
ΔCTS. Indicates that CTSn input (or MCR[1] in Loopback mode) has changed  
state. Cleared on a read.  
[1] The primary inputs RIn, CDn, CTSn, DSRn are all active LOW, but their registered equivalents in the MSR  
and MCR (in Loopback) registers are active HIGH.  
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5 V, 2.2 V and 2.5 V dual UART, 5 Mbit/s (max.), with 64-byte FIFOs  
7.8 Interrupt Enable Register (IER)  
The Interrupt Enable Register (IER) enables each of the six types of interrupt, receiver  
error, RHR interrupt, THR interrupt, Xoff received, or CTSn/RTSn change of state from  
LOW to HIGH. The INTA/INTB output signal is activated in response to interrupt  
generation. Table 16 shows Interrupt Enable Register bit settings.  
Table 16. 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  
RTS interrupt enable.  
6
5
4
3
IER[6][1]  
IER[5][1]  
IER[4][1]  
IER[3]  
logic 0 = disable the RTS interrupt (normal default condition)  
logic 1 = enable the RTS interrupt  
Xoff interrupt.  
logic 0 = disable the Xoff interrupt (normal default condition)  
logic 1 = enable the Xoff interrupt  
Sleep mode.  
logic 0 = disable Sleep mode (normal default condition)  
logic 1 = enable Sleep mode. See Section 6.7 “Sleep mode” for details.  
Modem Status Interrupt.  
logic 0 = disable the Modem Status Register interrupt (normal default  
condition)  
logic 1 = enable the Modem Status Register interrupt  
Receive Line Status interrupt.  
2
1
0
IER[2]  
IER[1]  
IER[0]  
logic 0 = disable the receiver line status interrupt (normal default condition)  
logic 1 = enable the receiver line status interrupt  
Transmit Holding Register interrupt.  
logic 0 = disable the THR interrupt (normal default condition)  
logic 1 = enable the THR interrupt  
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, i.e., EFR[4] is a write enable. Re-enabling IER[1] will not  
cause a new interrupt if the THR is below the threshold.  
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5 V, 2.2 V and 2.5 V dual UART, 5 Mbit/s (max.), with 64-byte FIFOs  
7.9 Interrupt Identification Register (IIR)  
The IIR is a read-only 8-bit register which provides the source of the interrupt in a  
prioritized manner. Table 17 shows Interrupt Identification Register bit settings.  
Table 17. Interrupt Identification Register bits description  
Bit  
7:6  
5
Symbol  
IIR[7:6]  
IIR[5]  
Description  
Mirror the contents of FCR[0]  
RTSn/CTSn LOW-to-HIGH change of state  
1 = Xoff/Special character has been detected  
3-bit encoded interrupt. See Table 18.  
Interrupt status.  
4
IIR[4]  
3:1  
0
IIR[3:1]  
IIR[0]  
logic 0 = an interrupt is pending  
logic 1 = no interrupt is pending  
The interrupt priority list is shown in Table 18.  
Table 18. Interrupt priority list  
Priority IIR[5] IIR[4] IIR[3] IIR[2] IIR[1] IIR[0] Source of the interrupt  
level  
1
2
2
3
4
5
0
0
0
0
0
0
0
0
0
0
0
1
0
1
0
0
0
0
1
1
1
0
0
0
1
0
0
1
0
0
0
0
0
0
0
0
Receiver Line Status error  
Receiver time-out interrupt  
RHR interrupt  
THR interrupt  
Modem interrupt  
Received Xoff signal/ special  
character  
6
1
0
0
0
0
0
CTSn, RTSn change of state from  
active (LOW) to inactive (HIGH)  
7.10 Enhanced Feature Register (EFR)  
This 8-bit register enables or disables the enhanced features of the UART. Table 19  
shows the Enhanced Feature Register bit settings.  
Table 19. Enhanced Feature 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 CTSn 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 RTSn 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.  
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5 V, 2.2 V and 2.5 V dual UART, 5 Mbit/s (max.), with 64-byte FIFOs  
Table 19. Enhanced Feature Register bits description …continued  
Bit Symbol Description  
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 logic 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] can  
be modified, i.e., this bit is therefore a write enable.  
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[0:3])”.  
7.11 Divisor latches (DLL, DLM)  
These are two 8-bit registers which store the 16-bit divisor for generation of the baud clock  
in the baud rate generator. DLM stores the most significant part of the divisor. DLL stores  
the least significant part of the divisor.  
Note that DLL and DLM can only be written to before Sleep mode is enabled, i.e., before  
IER[4] is set.  
7.12 Transmission Control Register (TCR)  
This 8-bit register is used to store the receive FIFO threshold levels to stop/start  
transmission during hardware/software flow control. Table 20 shows Transmission Control  
Register bit settings.  
Table 20. Transmission Control Register bits description  
Bit  
7:4  
3:0  
Symbol  
TCR[7:4]  
TCR[3:0]  
Description  
receive FIFO trigger level to resume transmission (0 to 60).  
receive FIFO trigger level to halt transmission (0 to 60).  
TCR trigger levels are available from 0 bytes to 60 bytes with a granularity of four.  
Remark: TCR can only be written to when EFR[4] = logic 1 and MCR[6] = 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.  
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5 V, 2.2 V and 2.5 V dual UART, 5 Mbit/s (max.), with 64-byte FIFOs  
7.13 Trigger Level Register (TLR)  
This 8-bit register is pulsed to store the transmit and received FIFO trigger levels used for  
DMA and interrupt generation. Trigger levels from 4 to 60 can be programmed with a  
granularity of 4. Table 21 shows trigger level register bit settings.  
Table 21. Trigger Level Register bits description  
Bit  
7:4  
3:0  
Symbol  
TLR[7:4]  
TLR[3:0]  
Description  
receive FIFO trigger levels (4 to 60), number of characters available  
transmit FIFO trigger levels (4 to 60), number of spaces available  
Remark: TLR can only be written to when EFR[4] = logic 1 and MCR[6] = logic 1. If  
TLR[3:0] or TLR[7:4] are logic 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 bytes to 60 bytes are available with a granularity of four. The TLR should be  
programmed for N4, where N is the desired trigger level.  
When the trigger level setting in TLR is zero, the SC16C752B 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,  
i.e., ‘00’.  
7.14 FIFO ready register  
The FIFO ready register provides real-time status of the transmit and receive FIFOs of  
both channels.  
Table 22. FIFO Ready Register bits description  
Bit  
7:6  
5
Symbol  
Description  
FIFO Rdy[7:6]  
FIFO Rdy[5]  
FIFO Rdy[4]  
FIFO Rdy[3:2]  
FIFO Rdy[1]  
FIFO Rdy[0]  
unused; always 0  
receive FIFO B status. Related to DMA.  
receive FIFO A status. Related to DMA.  
unused; always 0  
4
3:2  
1
transmit FIFO B status. Related to DMA.  
transmit FIFO A status. Related to DMA.  
0
The FIFO Rdy register is a read-only register that can be accessed when any of the two  
UARTs is selected CSA or CSB = logic 0, MCR[2] (FIFO Rdy Enable) is a logic 1, and  
loopback is disabled. The address is 111.  
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5 V, 2.2 V and 2.5 V dual UART, 5 Mbit/s (max.), with 64-byte FIFOs  
8. Programmer’s guide  
The base set of registers that is used during high-speed data transfer have a  
straightforward access method. The extended function registers require special access  
bits to be decoded along with the address lines. The following guide will help with  
programming these registers. Note that the descriptions below are for individual register  
access. Some streamlining through interleaving can be obtained when programming all  
the registers.  
Table 23. Register programming guide  
Command  
Actions  
Read LCR (03h), save in temp  
Set baud rate to VALUE1, VALUE2  
Set LCR (03h) to 80h  
Set DLL (00h) to VALUE1  
SET DLM (01h) to VALUE2  
Set LCR (03h) to temp  
Set Xoff1, Xon1 to VALUE1, VALUE2  
Set Xoff2, Xon2 to VALUE1, VALUE2  
Read LCR (03h), save in temp  
Set LCR (03h) to BFh  
Set Xoff1 (06h) to VALUE1  
SET Xon1 (04h) to VALUE2  
Set LCR (03h) to temp  
Read LCR (03h), save in temp  
Set LCR (03h) to BFh  
Set Xoff2 (07h) to VALUE1  
SET Xon2 (05h) to VALUE2  
Set LCR (03h) to temp  
Set software flow control mode to VALUE  
Set flow control threshold to VALUE  
Read LCR (03h), save in temp  
Set LCR (03h) to BFh  
Set EFR (02h) to VALUE  
Set LCR (03h) to temp  
Read LCR (03h), save in temp1  
Set LCR (03h) to BFh  
Read EFR (02h), save in temp2  
Set EFR (02h) to 10h + temp2  
Set LCR (03h) to 00h  
Read MCR (04h), save in temp3  
Set MCR (04h) to 40h + temp3  
Set TCR (06h) to VALUE  
Set MCR (04h) to temp3  
Set LCR (03h) to BFh  
Set EFR (02h) to temp2  
Set LCR (03h) to temp1  
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5 V, 2.2 V and 2.5 V dual UART, 5 Mbit/s (max.), with 64-byte FIFOs  
Table 23. Register programming guide …continued  
Command Actions  
Read LCR (03h), save in temp1  
Set TX FIFO and RX FIFO thresholds  
to VALUE  
Set LCR (03h) to BFh  
Read EFR (02h), save in temp2  
Set EFR (02h) to 10h + temp2  
Set LCR (03h) to 00h  
Read MCR (04h), save in temp3  
Set MCR (04h) to 40h + temp3  
Set TLR (07h) to VALUE  
Set MCR (04h) to temp3  
Set LCR (03h) to BFh  
Set EFR (02h) to temp2  
Set LCR (03h) to temp1  
Read FIFO Rdy register  
Read MCR (04h), save in temp1  
Set temp2 = temp1 × EFh[1]  
Set MCR (04h) = 40h + temp2  
Read FFR (07h), save in temp2  
Pass temp2 back to host  
Set MCR (04h) to temp1  
Set prescaler value to divide-by-1  
Read LCR (03h), save in temp1  
Set LCR (03h) to BFh  
Read EFR (02h), save in temp2  
Set EFR (02h) to 10h + temp2  
Set LCR (03h) to 00h  
Read MCR (04h), save in temp3  
Set MCR (04h) to temp3 × 7Fh[1]  
Set LCR (03h) to BFh  
Set EFR (02h) to temp2  
Set LCR (03h) to temp1  
Set prescaler value to divide-by-4  
Read LCR (03h), save in temp1  
Set LCR (03h) to BFh  
Read EFR (02h), save in temp2  
Set EFR (02h) to 10h + temp2  
Set LCR (03h) to 00h  
Read MCR (04h), save in temp3  
Set MCR (04h) to temp3 + 80h  
Set LCR (03h) to BFh  
Set EFR (02h) to temp2  
Set LCR (03h) to temp1  
[1] × sign here means bit-AND.  
SC16C752B  
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Product data sheet  
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32 of 47  
 
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NXP Semiconductors  
5 V, 2.2 V and 2.5 V dual UART, 5 Mbit/s (max.), with 64-byte FIFOs  
9. Limiting values  
Table 24. Limiting values  
In accordance with the Absolute Maximum Rating System (IEC 60134).  
Symbol  
VCC  
Parameter  
Conditions  
Min  
Max  
7
Unit  
V
supply voltage  
-
Vn  
voltage on any other pin  
at D7 to D0 pins  
GND 0.3  
GND 0.3  
40  
VCC + 0.3  
5.3  
V
at any input only pin  
operating in free-air  
V
Tamb  
Tstg  
ambient temperature  
storage temperature  
+85  
°C  
°C  
65  
+150  
10. Static characteristics  
Table 25. Static characteristics  
VCC = 2.5 V, 3.3 V ± 10 % or 5 V ± 10 %.  
Symbol Parameter  
Conditions  
VCC = 2.5 V  
Typ  
VCC 10 % VCC VCC + 10 % VCC 10 % VCC VCC + 10 % V  
VCC = 3.3 V or 5 V  
Unit  
Min  
Max  
Min  
Typ  
Max  
VCC  
VI  
supply voltage  
input voltage  
0
-
-
VCC  
VCC  
0
-
-
VCC  
VCC  
V
V
[1]  
[1]  
VIH  
HIGH-level input  
voltage  
1.6  
2.0  
VIL  
LOW-level input  
voltage  
-
-
0.65  
-
-
0.8  
V
[2]  
[3]  
[4]  
[3]  
[4]  
[3]  
[4]  
[3]  
[4]  
VO  
output voltage  
0
-
VCC  
0
-
VCC  
V
VOH  
HIGH-level  
output voltage  
IOH = 8 mA  
IOH = 4 mA  
IOH = 800 μA  
IOH = 400 μA  
-
-
-
-
2.0  
-
-
-
V
-
-
2.0  
-
V
1.85  
-
-
-
-
-
V
1.85  
-
-
-
-
-
V
VOL  
LOW-level output IOL = 8 mA  
voltage[5]  
-
-
-
-
-
0.4  
0.4  
-
V
IOL = 4 mA  
-
-
-
-
-
V
IOL = 2 mA  
IOL = 1.6 mA  
-
-
0.4  
0.4  
18  
+85  
-
-
V
-
-
-
-
-
-
-
-
-
V
Ci  
input capacitance  
18  
+85  
pF  
°C  
Tamb  
ambient  
temperature  
operating  
f = 5 MHz  
40  
+25  
40  
+25  
[6]  
Tj  
junction  
temperature  
0
25  
125  
0
25  
125  
°C  
δ
clock duty cycle  
supply current  
-
-
-
50  
-
-
-
-
-
50  
-
-
%
[7]  
[8]  
ICC  
3.5  
50  
4.5  
50  
mA  
μA  
ICC(sleep) sleep mode  
supply current  
-
-
[1] Meets TTL levels, VIH(min) = 2 V and VIL(max) = 0.8 V on non-hysteresis inputs.  
[2] Applies for external output buffers.  
[3] These parameters apply for D7 to D0.  
[4] These parameters apply for DTRA, DTRB, INTA, INTB, RTSA, RTSB, RXRDYA, RXRDYB, TXRDYA, TXRDYB, TXA, TXB.  
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Product data sheet  
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NXP Semiconductors  
5 V, 2.2 V and 2.5 V dual UART, 5 Mbit/s (max.), with 64-byte FIFOs  
[5] Except XTAL2, VOL = 1 V typical.  
[6] These junction temperatures reflect simulated conditions. Absolute maximum junction temperature is 150 °C. The customer is  
responsible for verifying junction temperature.  
[7] Measurement condition, normal operation other than Sleep mode:  
VCC = 3.3 V; Tamb = 25 °C. Full duplex serial activity on all two serial (UART) channels at the clock frequency specified in the  
recommended operating conditions with divisor of 1.  
[8] Sleep mode current might be higher if there is activity on the UART data bus during Sleep mode.  
11. Dynamic characteristics  
Table 26. Dynamic characteristics  
Tamb = 40 °C to +85 °C; VCC = 2.5 V, 3.3 V ± 10 % or 5 V ± 10 %, unless specified otherwise.  
Symbol Parameter  
Conditions  
VCC = 2.5 V  
VCC = 3.3 V or 5 V Unit  
Min  
Max  
-
Min  
Max  
td1  
IOR delay from chip select  
read cycle delay  
10  
20  
-
0
20  
-
-
-
ns  
ns  
ns  
ns  
ns  
ns  
ns  
ns  
ns  
s
td2  
25 pF load  
25 pF load  
25 pF load  
-
td3  
delay from IOR to data  
77  
26  
td4  
data disable time  
-
15  
-
15  
td5  
IOW delay from chip select  
write cycle delay  
10  
25  
-
-
10  
25  
-
-
td6  
-
-
td7  
delay from IOW to output  
25 pF load  
25 pF load  
25 pF load  
100  
100  
100  
1TRCLK  
100  
100  
33  
td8  
delay to set interrupt from modem input  
delay to reset interrupt from IOR  
delay from stop to set interrupt  
delay from IOR to reset interrupt  
delay from start to set interrupt  
delay from IOW to transmit start  
delay from IOW to reset interrupt  
delay from stop to set RXRDYn  
delay from IOR to reset RXRDYn  
delay from IOW to set TXRDYn  
delay from start to reset TXRDYn  
-
-
24  
td9  
-
-
24  
[1]  
[1]  
td10  
td11  
td12  
td13  
td14  
td15  
td16  
td17  
td18  
td19  
-
-
1TRCLK  
29  
25 pF load  
-
-
ns  
ns  
s
-
-
100  
[1]  
[1]  
8
-
24TRCLK  
100  
8
-
24TRCLK  
70  
ns  
s
[1]  
[1]  
-
1TRCLK  
100  
-
1TRCLK  
75  
-
-
ns  
ns  
s
-
100  
-
70  
[1]  
[1]  
-
16TRCLK  
20  
-
16TRCLK  
20  
delay between successive assertion of  
IOW and IOR  
-
-
ns  
th1  
th2  
th3  
th4  
th5  
chip select hold time from IOR  
chip select hold time from IOW  
data hold time  
0
0
-
-
-
-
-
0
0
-
-
-
-
-
ns  
ns  
ns  
ns  
ns  
15  
0
15  
0
address hold time  
hold time from XTAL1 clock HIGH-to-LOW  
transition to IOW or IOR release  
20  
20  
tp1  
clock cycle period  
10  
10  
-
-
-
6
6
-
-
ns  
tp2  
clock cycle period  
ns  
[2]  
[3]  
fXTAL1  
frequency on pin XTAL1  
48  
-
-
80  
-
MHz  
ns  
tw(RESET) pulse width on pin RESET  
100  
0
40  
0
tsu1  
address set-up time  
-
-
ns  
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Product data sheet  
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34 of 47  
 
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NXP Semiconductors  
5 V, 2.2 V and 2.5 V dual UART, 5 Mbit/s (max.), with 64-byte FIFOs  
Table 26. Dynamic characteristics …continued  
Tamb = 40 °C to +85 °C; VCC = 2.5 V, 3.3 V ± 10 % or 5 V ± 10 %, unless specified otherwise.  
Symbol Parameter  
Conditions  
VCC = 2.5 V  
VCC = 3.3 V or 5 V Unit  
Min  
Max  
Min  
16  
Max  
tsu2  
tsu3  
data set-up time  
16  
20  
-
-
-
-
ns  
ns  
set-up time from IOW or IOR assertion to  
XTAL1 clock LOW-to-HIGH transition  
20  
tw1  
tw2  
IOR strobe width  
IOW strobe width  
77  
30  
-
-
30  
30  
-
-
ns  
ns  
[1] RCLK is an internal signal derived from Divisor Latch LSB (DLL) and Divisor Latch MSB (DLM) divisor latches.  
[2] Applies to external clock; crystal oscillator max 24 MHz.  
[3] Reset pulse must happen when CSA, CSB, IOR, IOW are inactive.  
11.1 Timing diagrams  
valid  
address  
A0 to A2  
t
h4  
t
su1  
active  
CSA, CSB  
t
t
h1  
d1  
t
w1  
t
d2  
IOR  
active  
t
t
d3  
d4  
D0 to D7  
data  
002aaa235  
Fig 14. General read timing  
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Product data sheet  
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NXP Semiconductors  
5 V, 2.2 V and 2.5 V dual UART, 5 Mbit/s (max.), with 64-byte FIFOs  
valid  
address  
A0 to A2  
t
t
h4  
su1  
active  
CSA, CSB  
t
t
h2  
d5  
t
w2  
t
d6  
IOW  
active  
t
t
h3  
su2  
D0 to D7  
data  
002aaa236  
Fig 15. General write timing  
active  
IOW  
t
d7  
RTSA, RTSB  
DTRA, DTRB  
change of state  
change of state  
CDA, CDB  
CTSA, CTSB  
DSRA, DSRB  
change of state  
change of state  
t
d8  
t
d8  
INTA, INTB  
active  
active  
active  
active  
active  
active  
t
d9  
IOR  
t
d8  
change of state  
RIA, RIB  
002aaa238  
Fig 16. Modem input/output timing  
SC16C752B  
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Product data sheet  
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36 of 47  
SC16C752B  
NXP Semiconductors  
5 V, 2.2 V and 2.5 V dual UART, 5 Mbit/s (max.), with 64-byte FIFOs  
next  
data  
Start  
bit  
parity Stop Start  
bit  
bit  
bit  
data bits (0 to 7)  
RXA, RXB  
D0  
D1  
D2  
D3  
D4  
D5  
D6  
D7  
5 data bits  
6 data bits  
7 data bits  
t
d10  
active  
INTA, INTB  
t
d11  
active  
IOR  
16 baud rate clock  
002aaa239  
Fig 17. Receive timing  
next  
data  
start  
bit  
parity stop start  
bit bit  
bit  
data bits (0 to 7)  
D3 D4  
D0  
D1  
D2  
D5  
D6  
D7  
RXA, RXB  
t
d15  
active data  
ready  
RXRDYA  
RXRDYB  
t
d16  
active  
IOR  
002aab240  
Fig 18. Receive ready timing in non-FIFO mode  
SC16C752B  
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Product data sheet  
Rev. 6 — 30 November 2010  
37 of 47  
SC16C752B  
NXP Semiconductors  
5 V, 2.2 V and 2.5 V dual UART, 5 Mbit/s (max.), with 64-byte FIFOs  
start  
bit  
parity stop  
bit  
bit  
data bits (0 to 7)  
D3 D4  
D0  
D1  
D2  
D5  
D6  
D7  
RXA, RXB  
first byte that  
reaches the  
trigger level  
t
d15  
active data  
ready  
RXRDYA  
RXRDYB  
t
d16  
active  
IOR  
002aaa241  
Fig 19. Receive ready timing in FIFO mode  
next  
data  
Start  
bit  
parity Stop Start  
bit bit bit  
data bits (0 to 7)  
D3 D4  
D0  
D1  
D2  
D5  
D6  
D7  
TXA, TXB  
5 data bits  
6 data bits  
7 data bits  
t
d12  
active  
TX ready  
INTA, INTB  
IOW  
t
t
d14  
d13  
active  
active  
16 baud rate clock  
002aaa242  
Fig 20. Transmit timing  
SC16C752B  
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Product data sheet  
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38 of 47  
SC16C752B  
NXP Semiconductors  
5 V, 2.2 V and 2.5 V dual UART, 5 Mbit/s (max.), with 64-byte FIFOs  
next  
data  
start  
bit  
parity stop start  
bit  
bit  
bit  
data bits (0 to 7)  
D3 D4  
TXA, TXB  
D0  
D1  
D2  
D5  
D6  
D7  
active  
IOW  
D0 to D7  
byte #1  
t
d18  
t
d17  
TXRDYA  
TXRDYB  
active  
transmitter ready  
transmitter  
not ready  
002aaa243  
Fig 21. Transmit ready timing in non-FIFO mode  
start  
bit  
parity stop  
bit bit  
data bits (0 to 7)  
D3 D4  
D0  
D1  
D2  
D5  
D6  
D7  
TXA, TXB  
5 data bits  
6 data bits  
7 data bits  
IOW  
active  
t
d18  
D0 to D7  
byte #64  
t
d17  
TXRDYA  
TXRDYB  
trigger  
lead  
002aaa244  
Fig 22. Transmit ready timing in FIFO mode  
SC16C752B  
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Product data sheet  
Rev. 6 — 30 November 2010  
39 of 47  
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NXP Semiconductors  
5 V, 2.2 V and 2.5 V dual UART, 5 Mbit/s (max.), with 64-byte FIFOs  
12. Package outline  
LQFP48: plastic low profile quad flat package; 48 leads; body 7 x 7 x 1.4 mm  
SOT313-2  
c
y
X
36  
25  
A
E
37  
24  
Z
E
e
H
E
A
2
A
(A )  
3
A
1
w M  
p
θ
pin 1 index  
b
L
p
L
13  
48  
detail X  
1
12  
Z
v M  
D
A
e
w M  
b
p
D
B
H
v
M
B
D
0
2.5  
5 mm  
scale  
DIMENSIONS (mm are the original dimensions)  
A
(1)  
(1)  
(1)  
(1)  
UNIT  
A
A
A
b
c
D
E
e
H
D
H
L
L
v
w
y
Z
Z
E
θ
1
2
3
p
E
p
D
max.  
7o  
0o  
0.20 1.45  
0.05 1.35  
0.27 0.18 7.1  
0.17 0.12 6.9  
7.1  
6.9  
9.15 9.15  
8.85 8.85  
0.75  
0.45  
0.95 0.95  
0.55 0.55  
1.6  
mm  
0.25  
0.5  
1
0.2 0.12 0.1  
Note  
1. Plastic or metal protrusions of 0.25 mm maximum per side are not included.  
REFERENCES  
OUTLINE  
EUROPEAN  
PROJECTION  
ISSUE DATE  
VERSION  
IEC  
JEDEC  
JEITA  
00-01-19  
03-02-25  
SOT313-2  
136E05  
MS-026  
Fig 23. Package outline SOT313-2 (LQFP48)  
SC16C752B  
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Product data sheet  
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40 of 47  
 
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NXP Semiconductors  
5 V, 2.2 V and 2.5 V dual UART, 5 Mbit/s (max.), with 64-byte FIFOs  
HVQFN32: plastic thermal enhanced very thin quad flat package; no leads;  
32 terminals; body 5 x 5 x 0.85 mm  
SOT617-1  
B
A
D
terminal 1  
index area  
A
A
1
E
c
detail X  
C
e
1
y
y
e
1/2 e  
v
M
M
b
C
C
A B  
C
1
w
9
16  
L
17  
8
e
e
E
h
2
1/2 e  
1
24  
terminal 1  
index area  
32  
25  
X
D
h
0
2.5  
5 mm  
scale  
DIMENSIONS (mm are the original dimensions)  
(1)  
A
(1)  
(1)  
UNIT  
A
b
c
E
e
e
e
2
y
D
D
E
L
v
w
y
1
1
h
1
h
max.  
0.05 0.30  
0.00 0.18  
5.1  
4.9  
3.25  
2.95  
5.1  
4.9  
3.25  
2.95  
0.5  
0.3  
mm  
0.05 0.1  
1
0.2  
0.5  
3.5  
3.5  
0.1  
0.05  
Note  
1. Plastic or metal protrusions of 0.075 mm maximum per side are not included.  
REFERENCES  
OUTLINE  
EUROPEAN  
PROJECTION  
ISSUE DATE  
VERSION  
IEC  
JEDEC  
JEITA  
01-08-08  
02-10-18  
SOT617-1  
- - -  
MO-220  
- - -  
Fig 24. Package outline SOT617-1 (HVQFN32)  
SC16C752B  
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Product data sheet  
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41 of 47  
SC16C752B  
NXP Semiconductors  
5 V, 2.2 V and 2.5 V dual UART, 5 Mbit/s (max.), with 64-byte FIFOs  
13. 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”.  
13.1 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.  
13.2 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  
13.3 Wave soldering  
Key characteristics in wave soldering are:  
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  
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NXP Semiconductors  
5 V, 2.2 V and 2.5 V dual UART, 5 Mbit/s (max.), with 64-byte FIFOs  
13.4 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 25) 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 27 and 28  
Table 27. SnPb eutectic process (from J-STD-020C)  
Package thickness (mm) Package reflow temperature (°C)  
Volume (mm3)  
< 350  
235  
350  
220  
< 2.5  
2.5  
220  
220  
Table 28. Lead-free process (from J-STD-020C)  
Package thickness (mm) Package reflow temperature (°C)  
Volume (mm3)  
< 350  
260  
350 to 2000  
> 2000  
260  
< 1.6  
260  
250  
245  
1.6 to 2.5  
> 2.5  
260  
245  
250  
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 25.  
SC16C752B  
All information provided in this document is subject to legal disclaimers.  
© NXP B.V. 2010. All rights reserved.  
Product data sheet  
Rev. 6 — 30 November 2010  
43 of 47  
 
SC16C752B  
NXP Semiconductors  
5 V, 2.2 V and 2.5 V dual UART, 5 Mbit/s (max.), with 64-byte FIFOs  
maximum peak temperature  
= MSL limit, damage level  
temperature  
minimum peak temperature  
= minimum soldering temperature  
peak  
temperature  
time  
001aac844  
MSL: Moisture Sensitivity Level  
Fig 25. Temperature profiles for large and small components  
For further information on temperature profiles, refer to Application Note AN10365  
“Surface mount reflow soldering description”.  
14. Abbreviations  
Table 29. Abbreviations  
Acronym  
CPU  
Description  
Central Processing Unit  
DMA  
Direct Memory Access  
FIFO  
First In, First Out  
TTL  
Transistor-Transistor Logic  
Universal Asynchronous Receiver/Transmitter  
UART  
15. Revision history  
Table 30. Revision history  
Document ID  
Release date  
Data sheet status  
Change notice  
Supersedes  
SC16C752B v.6 20101130  
Modifications:  
Product data sheet  
-
SC16C752B v.5  
Table 2 “Pin description”: signal names CTSB, DTRB, OPB and RXRDYB are corrected by adding  
overbar to indicate they are active LOW signals (CTSB, DTRB, OPB and RXRDYB)  
Table 25 “Static characteristics”: Table note [1] corrected from “VIO(min) = 2 V and VIH(max) = 0.8 V”  
to “VIH(min) = 2 V and VIL(max) = 0.8 V”  
SC16C752B v.5 20081002  
SC16C752B v.4 20060714  
SC16C752B v.3 20041214  
SC16C752B v.2 20040527  
SC16C752B v.1 20040326  
Product data sheet  
Product data sheet  
Product data  
-
-
-
-
-
SC16C752B v.4  
SC16C752B v.3  
SC16C752B v.2  
SC16C752B v.1  
-
Product data  
Product data  
SC16C752B  
All information provided in this document is subject to legal disclaimers.  
© NXP B.V. 2010. All rights reserved.  
Product data sheet  
Rev. 6 — 30 November 2010  
44 of 47  
 
 
SC16C752B  
NXP Semiconductors  
5 V, 2.2 V and 2.5 V dual UART, 5 Mbit/s (max.), with 64-byte FIFOs  
16. Legal information  
16.1 Data sheet status  
Document status[1][2]  
Product status[3]  
Development  
Definition  
Objective [short] data sheet  
This document contains data from the objective specification for product development.  
This document contains data from the preliminary specification.  
This document contains the product specification.  
Preliminary [short] data sheet Qualification  
Product [short] data sheet Production  
[1]  
[2]  
[3]  
Please consult the most recently issued document before initiating or completing a design.  
The term ‘short data sheet’ is explained in section “Definitions”.  
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.  
malfunction of an NXP Semiconductors product can reasonably be expected  
16.2 Definitions  
to result in personal injury, death or severe property or environmental  
damage. NXP Semiconductors accepts no liability for inclusion and/or use of  
NXP Semiconductors products in such equipment or applications and  
therefore such inclusion and/or use is at the customer’s own risk.  
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.  
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.  
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.  
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.  
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.  
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.  
16.3 Disclaimers  
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.  
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.  
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.  
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.  
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.  
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.  
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 national authorities.  
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  
SC16C752B  
All information provided in this document is subject to legal disclaimers.  
© NXP B.V. 2010. All rights reserved.  
Product data sheet  
Rev. 6 — 30 November 2010  
45 of 47  
 
 
 
 
SC16C752B  
NXP Semiconductors  
5 V, 2.2 V and 2.5 V dual UART, 5 Mbit/s (max.), with 64-byte FIFOs  
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  
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.  
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  
16.4 Trademarks  
Notice: All referenced brands, product names, service names and trademarks  
are the property of their respective owners.  
17. Contact information  
For more information, please visit: http://www.nxp.com  
For sales office addresses, please send an email to: salesaddresses@nxp.com  
SC16C752B  
All information provided in this document is subject to legal disclaimers.  
© NXP B.V. 2010. All rights reserved.  
Product data sheet  
Rev. 6 — 30 November 2010  
46 of 47  
 
 
SC16C752B  
NXP Semiconductors  
5 V, 2.2 V and 2.5 V dual UART, 5 Mbit/s (max.), with 64-byte FIFOs  
18. Contents  
1
2
3
4
General description. . . . . . . . . . . . . . . . . . . . . . 1  
8
Programmer’s guide . . . . . . . . . . . . . . . . . . . . 31  
Limiting values . . . . . . . . . . . . . . . . . . . . . . . . 33  
Static characteristics . . . . . . . . . . . . . . . . . . . 33  
Dynamic characteristics. . . . . . . . . . . . . . . . . 34  
Timing diagrams. . . . . . . . . . . . . . . . . . . . . . . 35  
Package outline. . . . . . . . . . . . . . . . . . . . . . . . 40  
Features and benefits . . . . . . . . . . . . . . . . . . . . 1  
Ordering information. . . . . . . . . . . . . . . . . . . . . 2  
Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . 3  
9
10  
11  
11.1  
12  
5
5.1  
5.2  
Pinning information. . . . . . . . . . . . . . . . . . . . . . 4  
Pinning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4  
Pin description . . . . . . . . . . . . . . . . . . . . . . . . . 5  
13  
Soldering of SMD packages. . . . . . . . . . . . . . 42  
Introduction to soldering. . . . . . . . . . . . . . . . . 42  
Wave and reflow soldering. . . . . . . . . . . . . . . 42  
Wave soldering . . . . . . . . . . . . . . . . . . . . . . . 42  
Reflow soldering . . . . . . . . . . . . . . . . . . . . . . 43  
6
6.1  
6.2  
Functional description . . . . . . . . . . . . . . . . . . . 7  
Trigger levels . . . . . . . . . . . . . . . . . . . . . . . . . . 7  
Hardware flow control. . . . . . . . . . . . . . . . . . . . 7  
Auto-RTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8  
Auto-CTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9  
Software flow control . . . . . . . . . . . . . . . . . . . . 9  
Receive flow control . . . . . . . . . . . . . . . . . . . . 10  
Transmit flow control. . . . . . . . . . . . . . . . . . . . 10  
Software flow control example . . . . . . . . . . . . 11  
Assumptions. . . . . . . . . . . . . . . . . . . . . . . . . . 11  
Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12  
Interrupts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13  
Interrupt mode operation . . . . . . . . . . . . . . . . 14  
Polled mode operation . . . . . . . . . . . . . . . . . . 14  
DMA operation . . . . . . . . . . . . . . . . . . . . . . . . 15  
Single DMA transfers  
13.1  
13.2  
13.3  
13.4  
6.2.1  
6.2.2  
6.3  
6.3.1  
6.3.2  
6.3.3  
6.3.3.1  
6.4  
14  
15  
Abbreviations . . . . . . . . . . . . . . . . . . . . . . . . . 44  
Revision history . . . . . . . . . . . . . . . . . . . . . . . 44  
16  
Legal information . . . . . . . . . . . . . . . . . . . . . . 45  
Data sheet status . . . . . . . . . . . . . . . . . . . . . . 45  
Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . 45  
Disclaimers . . . . . . . . . . . . . . . . . . . . . . . . . . 45  
Trademarks . . . . . . . . . . . . . . . . . . . . . . . . . . 46  
16.1  
16.2  
16.3  
16.4  
6.5  
17  
18  
Contact information . . . . . . . . . . . . . . . . . . . . 46  
Contents. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47  
6.5.1  
6.5.2  
6.6  
6.6.1  
(DMA mode 0/FIFO disable). . . . . . . . . . . . . . 15  
Transmitter . . . . . . . . . . . . . . . . . . . . . . . . . . . 15  
Receiver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15  
Block DMA transfers (DMA mode 1). . . . . . . . 16  
Transmitter . . . . . . . . . . . . . . . . . . . . . . . . . . . 16  
Receiver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16  
Sleep mode . . . . . . . . . . . . . . . . . . . . . . . . . . 16  
Break and time-out conditions . . . . . . . . . . . . 17  
Programmable baud rate generator . . . . . . . . 17  
6.6.1.1  
6.6.1.2  
6.6.2  
6.6.2.1  
6.6.2.2  
6.7  
6.8  
6.9  
7
Register descriptions . . . . . . . . . . . . . . . . . . . 19  
Receiver Holding Register (RHR). . . . . . . . . . 21  
Transmit Holding Register (THR) . . . . . . . . . . 21  
FIFO Control Register (FCR) . . . . . . . . . . . . . 22  
Line Control Register (LCR) . . . . . . . . . . . . . . 23  
Line Status Register (LSR). . . . . . . . . . . . . . . 24  
Modem Control Register (MCR). . . . . . . . . . . 25  
Modem Status Register (MSR). . . . . . . . . . . . 26  
Interrupt Enable Register (IER) . . . . . . . . . . . 27  
Interrupt Identification Register (IIR). . . . . . . . 28  
Enhanced Feature Register (EFR) . . . . . . . . . 28  
Divisor latches (DLL, DLM). . . . . . . . . . . . . . . 29  
Transmission Control Register (TCR). . . . . . . 29  
Trigger Level Register (TLR) . . . . . . . . . . . . . 30  
FIFO ready register . . . . . . . . . . . . . . . . . . . . 30  
7.1  
7.2  
7.3  
7.4  
7.5  
7.6  
7.7  
7.8  
7.9  
7.10  
7.11  
7.12  
7.13  
7.14  
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. 2010.  
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: 30 November 2010  
Document identifier: SC16C752B  
 

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