SPRUJ79 November 2024 F29H850TU , F29H859TU-Q1
When using the RTDMA with the RX FIFO, the RTDMA Burst Size (BURST_SIZE) must be no greater than RXFFIL to prevent the RTDMA from reading from an empty FIFO. To make sure that the RTDMA correctly receives all data from the RX FIFO, the RTDMA Burst Size can equal RXFFIL and also be an integer divisor of the total number of SPI transmissions.
For complete data reception, follow these steps:
To receive 200 words from SPI using the RTDMA:
NUM_WORDS = 200
RXFFIL: 4
DMA_TRANSFER_SIZE: (NUM_WORDS /RXFFIL) - 1 = (200/4) - 1 = 49 (50 transfers)
DMA_BURST_SIZE: 2(RXFFIL) - 1 = 2(4) - 1 = 7 (8 words per burst)