SPRUJ53B April 2024 – September 2024 TMS320F28P550SJ , TMS320F28P559SJ-Q1
When using the DMA with the TX FIFO, the DMA Burst Size (DMA_BURST_SIZE) must be no greater than 16 - TXFFIL, to prevent the DMA from writing to an already full FIFO. This leads to data loss and is not recommended.
For complete data transmission, follow these steps:
To transfer 128 words to SPI using the DMA:
NUM_WORDS: 128
TXFFIL: 8
DMA_TRANSFER_SIZE: (NUM_WORDS /(16 - TXFFIL)) - 1 = (128/8) - 1 = 15 (16 transfers)
DMA_BURST_SIZE: (16 - TXFFIL) - 1 = (16 - 8) - 1 = 7 (8 words per burst)