SPRUJ17H March 2022 – October 2024 AM2631 , AM2631-Q1 , AM2632 , AM2632-Q1 , AM2634 , AM2634-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 their 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_ALTC_.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.