sc16c751b NXP Semiconductors, sc16c751b Datasheet - Page 4

• Manufacturer Part Number: sc16c751b
• Description: 5 V, 3.3 V And 2.5 V Uart With 64-byte Fifos
• Manufacturer: NXP Semiconductors

NXP Semiconductors
SC16C751B_2
Product data sheet
5.2 Pin description
Table 2.
Symbol
A0
A1
A2
CS
CTS
D0
D1
D2
D3
D4
D5
D6
D7
INT
RESET
IOR
RTS
RX
TX
V
V
DD
SS
[1]
Pin description
Pin
14
13
12
6
18
20
21
22
23
24
1
2
3
15
17
11
16
4
5
19
10
Type
I
I
I
I
I
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
O
I
I
O
I
O
power
power
Rev. 02 — 10 October 2008
Description
Register select. A0 to A2 are used during read and write
operations to select the UART register to read from or write to.
Refer to
Chip select. When CS is LOW, the UART is selected.
Clear to send. CTS is a modem status signal. Its condition can be
checked by reading bit 4 (CTS) of the Modem Status Register
(MSR). MSR[3] ( CTS) indicates that CTS has changed states
since the last read from the MSR. If the modem status interrupt is
enabled when CTS changes levels and the auto-CTS mode is not
enabled, an interrupt is generated. CTS is also used in the
auto-CTS mode to control the transmitter.
Data bus. Eight data lines with 3-state outputs provide a
bidirectional path for data, control and status information between
the UART and the CPU.
Interrupt. When active (HIGH), INT informs the CPU that the UART
has an interrupt to be serviced. Four conditions that cause an
interrupt to be issued are: a receiver error, received data that is
available or timed out (FIFO mode only), an empty transmitter
holding register or an enabled modem status interrupt. INT is reset
(deactivated) either when the interrupt is serviced or as a result of a
Master Reset.
Master Reset. When active (HIGH), RESET clears most UART
registers and sets the levels of various output signals.
Read input. When IOR is active (LOW) while the UART is selected,
the CPU is allowed to read status information or data from a
selected UART register.
Request to send. When active, RTS informs the modem or data
set that the UART is ready to receive data. RTS is set to the active
level by setting the RTS Modem Control Register bit and is set to
the inactive (HIGH) level either as a result of a Master Reset or
during Loopback mode operations or by clearing bit 1 (RTS) of the
MCR. In the auto-RTS mode, RTS is set to the inactive level by the
receiver threshold control logic.
Serial data input. RX is serial data input from a connected
communications device.
Serial data output. TX is composite serial data output to a
connected communication device. TX is set to the marking (HIGH)
level as a result of Master Reset.
2.5 V, 3 V or 5 V supply voltage.
Ground voltage.
Table 3
5 V, 3.3 V and 2.5 V UART with 64-byte FIFOs
for register addresses.
SC16C751B
© NXP B.V. 2008. All rights reserved.
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