# Enabling and Disabling the SPI Module

Setting the EN bit enables the SPI peripheral. However, to reset or reconfigure the SPI mode, the EN bit must be cleared.

Setting the EN bit enables the SPI inputs and outputs: SDI, SDO, SCK_out, SCK_in, SS_out and SS_in. The pins for all of these inputs and outputs are selected by the PPS controls, and thus must have their functions mapped properly to the device pins to function. Refer to the “PPS - Peripheral Pin Select Module” chapter for more details.

SS_out and SCK_out must have the pins to which they are assigned set as outputs (TRIS bits must be ‘0’) to properly output. Clearing the TRIS bit of the SDO pin will cause the SPI module to always control that pin, but is not necessary for SDO functionality (see the Input and Output Polarity Control section).

Configurations selected by the following registers will not be changed while the EN bit is set:
• SPIxBAUD
• SPIxCON1
• SPIxCON0 (with the exception of clearing the EN bit)

Clearing the EN bit aborts any transmissions in progress, disables the setting of interrupt flags by hardware, and resets the FIFO occupancy (see the Transmit and Receive FIFOs section).