DSPIC30F datasheet(107/248 Pages) MICROCHIP

107 / 248 page

 2004 Microchip Technology Inc.

Preliminary

DS70083G-page 105

dsPIC30F

14.3

Slave Select Synchronization

The SSx pin allows a Synchronous Slave mode. The

SPI must be configured in SPI Slave mode with SSx pin

control enabled (SSEN = 1). When the SSx pin is low,

transmission and reception are enabled and the SDOx

pin is driven. When SSx pin goes high, the SDOx pin is

no longer driven. Also, the SPI module is re-

synchronized, and all counters/control circuitry are

reset. Therefore, when the SSx pin is asserted low

again, transmission/reception will begin at the MS bit

even if SSx had been de-asserted in the middle of a

transmit/receive.

14.4

SPI Operation During CPU Sleep

Mode

During Sleep mode, the SPI module is shutdown. If the

CPU enters Sleep mode while an SPI transaction is in

progress, then the transmission and reception is

aborted.

The transmitter and receiver will stop in Sleep mode.

However, register contents are not affected by entering

or exiting Sleep mode.

14.5

SPI Operation During CPU Idle

Mode

When the device enters Idle mode, all clock sources

remain functional. The SPISIDL bit (SPIxSTAT<13>)

selects if the SPI module will stop or continue on Idle. If

SPISIDL = 0, the module will continue to operate when

the CPU enters Idle mode. If SPISIDL = 1, the module

will stop when the CPU enters Idle mode.

DSPIC30F Datasheet(PDF) 107 Page - Microchip Technology