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MSPM33C321A: SysConfig Question about SPI-DMA

Keith Barkley
Guru 44215 points

Part Number: MSPM33C321A

In the DMA settings in the SPI peripheral what are the units of "Transfer Size"?

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Are they bytes or "words", i.e., the number of bytes in the source length setting?

  • 0
    Guru 103365 points

    The units are given by Source/Destination Length. Usually those are the same (e.g. one Byte in, one Byte out per transfer), but if e.g. Source=Byte and Destination=Long the overall source/destination sizes in memory would be different.

    I suppose a more natural term would be "Transfer Count", but the register is named DMAxSZ.

  • 0
    TI__Intellectual 2550 points

    Hello Keith, 

    Just as Bruce said, this refers to the count of DMA transfers.  It is not the number of bytes in your source buffer unless your configured DMA data width happens to be 8 bits.

    Best Regards, 

    Benedict Jojo