SPRUI33H November 2015 – June 2024 TMS320F280040-Q1 , TMS320F280040C-Q1 , TMS320F280041 , TMS320F280041-Q1 , TMS320F280041C , TMS320F280041C-Q1 , TMS320F280045 , TMS320F280048-Q1 , TMS320F280048C-Q1 , TMS320F280049 , TMS320F280049-Q1 , TMS320F280049C , TMS320F280049C-Q1
To configure both FSITX and RX modules for full duplex SPI master 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_MASTER_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 slave is across an isolation barrier and there is latency between TXCLK being launched and SPISOMI data being received on RXD0.