SPRUHX5I August 2014 – May 2024 TMS320F28374S , TMS320F28375S , TMS320F28375S-Q1 , TMS320F28376S , TMS320F28377S , TMS320F28377S-Q1 , TMS320F28378S , TMS320F28379S
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 /TXFFIL) – 1 = (128/8) – 1 = 15 (16 transfers)
DMA_BURST_SIZE: (16 – TXFFIL) – 1 = (16 – 8) – 1 = 7 (8 words per burst)