SPRUJ79 November 2024 F29H850TU , F29H859TU-Q1
Both the CPU and RTDMA have access to the SPI data registers using the internal peripheral bus. This access is limited to 16-bit register reads and writes. Each SPI module can generate two RTDMA events, SPITXDMA and SPIRXDMA. The RTDMA events are controlled by configuring the SPIFFTX.TXFFIL and SPIFFRX.RXFFIL appropriately. SPITXDMA activates when TXFFST is less than the interrupt level (TXFFIL). SPIRXDMA activates when RXFFST is greater than or equal to the interrupt level (RXFFIL).
The SPI must have FIFO enhancements enabled for the RTDMA triggers to be generated.
For more information on configuring the SPI for RTDMA transfers, refer to Section 41.3.8.
Figure 41-3 is a block diagram showing the RTDMA trigger generation from the SPI module.