DSPIC30F4012 datasheet(126/238 Pages) MICROCHIP

126 / 238 page

dsPIC30F4011/4012

DS70135G-page 126

18.9

Auto-Baud Support

To allow the system to determine baud rates of

received characters, the input can be optionally linked

to a selected capture input (IC1 for UART1, IC2 for

UART2). To enable this mode, the user must program

the input capture module to detect the falling and rising

edges of the Start bit.

18.10 UART Operation During CPU

Sleep and Idle Modes

18.10.1

UART OPERATION DURING CPU

SLEEP MODE

When the device enters Sleep mode, all clock sources

to the module are shut down and stay at logic ‘0’. If

entry into Sleep mode occurs while a transmission is

in progress, then the transmission is aborted. The

UxTX pin is driven to logic ‘1’. Similarly, if entry into

Sleep mode occurs while a reception is in progress,

then the reception is aborted. The UxSTA, UxMODE,

UxBRG, transmit and receive registers and buffers, are

not affected by Sleep mode.

If the WAKE bit (UxMODE<7>) is set before the device

enters Sleep mode, then a falling edge on the UxRX

pin will generate a receive interrupt. The Receive

Interrupt Select Mode bit (URXISEL) has no effect for

this function. If the receive interrupt is enabled, then

this will wake-up the device from Sleep. The UARTEN

bit must be set in order to generate a wake-up

interrupt.

18.10.2

UART OPERATION DURING CPU

IDLE MODE

For the UART, the USIDL bit selects if the module will

stop operation when the device enters Idle mode, or

whether the module will continue on Idle. If USIDL = 0,

the module will continue operation during Idle mode. If

USIDL = 1, the module will stop on Idle.

DSPIC30F4012 Datasheet(PDF) 126 Page - Microchip Technology