16.3. UART signals on pads

The signals connected to pads are listed in Table 16.1.

Table 16.1. Pad signal descriptions

Name

Direction

Description

nUART0CTS nUART1CTS nUART2CTS

Input

UART Clear To Send modem status signal, active LOW. The condition of this signal can be read from the UARTFR register.

nUART0DCD

Input

UART Data Carrier Detect modem status signal, active LOW. The condition of this signal can be read from the UARTFR register. (nUARTDCD is tied HIGH on UART1 and UART2.)

nUART0DSR

Input

UART Data Set Ready modem status signal, active LOW. The condition of this signal can be read from the UARTFR register. (nUARTDSR is tied HIGH on UART1 and UART2.)

nUART0RI

Input

UART Ring Indicator modem status signal, active LOW. The condition of this signal can be read from the UARTFR register. (RI is tied HIGH on UART1 and UART2.)

SIRIN0

Input

SIR Received Serial Data Input.

In the idle state, the signal remains in the marking state 1. When a light pulse is received which represents a logic 0, this signal is a 0.

(SIRIN is tied LOW on UART1 and UART2.)

UART0RXD UART1RXD UART2RXD

Input

UART Received Serial Data signal.

UARTCLKEXT

InputExternal clock reference for peripheral. This signal can be selected instead of the internal clock reference.

nSIROUT0

Output

SIR Transmitted Serial Data Output, active LOW. In the idle state, this signal remains 0 (the marking state). When this signal is set to 1, an infrared light pulse is generated which represents a logic 0 (spacing state).

(SIROUT is not used on UART1 and UART2.)

nUART0DTR

Output

UART Data Terminal Ready modem status signal, active LOW.

The reset value is 0.

(nUARTDTR is not used on UART1 and UART2.)

nUART0Out1 nUART0Out2

Output

UART modem status signal, active LOW.

The reset value is 0.

(nUARTOut1 is not used on UART1 and UART2.)

UART0TXD UART1TXD UART2TXD

Output

UART Transmit Serial Data.

Defaults to the marking state 1, when reset.

nUART0RTS nUART1RTS nUART2RTS

Output

UART Request To Send modem status signal, active LOW.

The reset value is 0.

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