SC16C751B datasheet(4/32 Pages) NXP

4 / 32 page

SC16C751B_2

Product data sheet

Rev. 02 — 10 October 2008

4 of 32

NXP Semiconductors

SC16C751B

5 V, 3.3 V and 2.5 V UART with 64-byte FIFOs

5.2 Pin description

Table 2.

Pin description

Symbol

Type

Description

operations to select the UART register to read from or write to.

Refer to Table 3 for register addresses.

Chip select. When CS is LOW, the UART is selected.

CTS

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.

I/O

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.

I/O

INT

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.

RESET

Master Reset. When active (HIGH), RESET clears most UART

registers and sets the levels of various output signals.

IOR

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.

RTS

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.

VDD

power

2.5 V, 3 V or 5 V supply voltage.

VSS[1]

power

Ground voltage.

SC16C751B Datasheet(PDF) 4 Page - NXP Semiconductors

SC16C751B Datasheet(HTML) 4 Page - NXP Semiconductors

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32

Datasheet Download

Link URL