![NXP Semiconductors LPC84x User Manual Download Page 287](http://html.mh-extra.com/html/nxp-semiconductors/lpc84x/lpc84x_user-manual_1721742287.webp)
UM11029
All information provided in this document is subject to legal disclaimers.
© NXP Semiconductors N.V. 2017. All rights reserved.
User manual
Rev. 1.0 — 16 June 2017
287 of 515
NXP Semiconductors
UM11029
Chapter 17: LPC84x USART0/1/2/3/4
17.4 Pin description
Table 321. USART pin description
Function
I/O
Type
Connect
to
Use register
Reference
Description
U0_TXD
O
external
to pin
any pin
PINASSIGN0
Transmitter output for USART0. Serial transmit data.
U0_RXD
I
external
to pin
any pin
PINASSIGN0
Receiver input for USART0.
U0_RTS
O
external
to pin
any pin
PINASSIGN0
Request To Send output for USART0. This signal
supports inter-processor communication through the
use of hardware flow control. This feature is active
when the USART RTS signal is configured to appear
on a device pin.
U0_CTS
I
external
to pin
any pin
PINASSIGN0
Clear To Send input for USART0. Active low signal
indicates that the external device that is in
communication with the USART is ready to accept
data. This feature is active when enabled by the
CTSEn bit in CFG register and when configured to
appear on a device pin. When de-asserted (high) by
the external device, the USART will complete
transmitting any character already in progress, then
stop until CTS is again asserted (low).
U0_SCLK I/O
external
to pin
any pin
PINASSIGN1
Serial clock input/output for USART0 n synchronous
mode.
U1_TXD
O
external
to pin
any pin
PINASSIGN1
Transmitter output for USART1. Serial transmit data.
U1_RXD
I
external
to pin
any pin
PINASSIGN1
Receiver input for USART1.
U1_RTS
O
external
to pin
any pin
PINASSIGN1
Request To Send output for USART1.
U1_CTS
I
external
to pin
any pin
PINASSIGN2
Clear To Send input for USART1.
U1_SCLK I/O
external
to pin
any pin
PINASSIGN2
Serial clock input/output for USART1 in synchronous
mode.
U2_TXD
O
external
to pin
any pin
PINASSIGN2
Transmitter output for USART2. Serial transmit data.
U2_RXD
I
external
to pin
any pin
PINASSIGN2
Receiver input for USART2.
U2_RTS
O
external
to pin
any pin
PINASSIGN3
Request To Send output for USART2.
U2_CTS
I
external
to pin
any pin
PINASSIGN3
Clear To Send input for USART2.
U2_SCLK I/O
external
to pin
any pin
PINASSIGN3
Serial clock input/output for USART2 in synchronous
mode.
U3_TXD
O
external
to pin
any pin
PINASSIGN11
Transmitter output for USART3. Serial transmit data.
U3_RXD
I
external
to pin
any pin
PINASSIGN12
Receiver input for USART3.