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
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)