SPRUIZ1B July 2023 – August 2024 TMS320F28P650DH , TMS320F28P650DK , TMS320F28P650SH , TMS320F28P650SK , TMS320F28P659DH-Q1 , TMS320F28P659DK-Q1 , TMS320F28P659SH-Q1
To configure both FSITX and RX modules for full duplex SPI controller operation, follow the initialization instructions for each module described in the preceding sections. Both FSITX and RX modules must set the respective SPI_MODE bits. This enables the SPI clocking scheme and signaling structures.
If internal clock loopback is desired, the FSIRX module must also set RX_MAIN_CTRL.SPI_PAIRING to 1. This internally connects TXCLK to RXCLK. If using internal clock loopback, the GPIO used for RXCLK can be reallocated to other application requirements.
If the application requires an external clock loopback, make sure that TXCLK is connected to RXCLK. This is required if the SPI peripheral is across an isolation barrier and there is latency between TXCLK being launched and SPIPOCI data being received on RXD0.