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TMS320F28379D: Can DMA have access to SPI-A while CLA has access to SPI-B

Ryan Edwards
Prodigy 225 points
Part Number: TMS320F28379D


I have an application where I would like to setup two SPI controllers for two external devices (one master IC and one slave IC).  My preferred solution is that SPI-A would be a CPU1 master controller with DMA support and SPI-B would be a CLA1 slave controller FIFO.  I see that the Peripheral Frame 2 (CpuSysRegs.SECMSEL.bit.PF2SEL) must be set either to CLA or DMA as the secondary master.  So does this mean that I can't allow the DMA to have access to SPI-A master concurrently while CLA has access to SPI-B slave?

  • 0
    TI__Guru** 115881 points

    Hi Ryan,

    So does this mean that I can't allow the DMA to have access to SPI-A master concurrently while CLA has access to SPI-B slave?

    Yes, your understanding is correct. Access to all SPI can be either from CLA or DMA of same CPU subsystem (e.g. CPU1). But you can have access to SPI-A from CPU1 DMA and SPI-B from CPU2 CLA.

    Regards

    Vivek Singh

  • 0
    Guru 30330 points
    Ryan,

    You are correct in your assessment. Using CLA with SPIB and DMA with SPIA is not possible. It is an all-or-nothing scheme for each peripheral frame. One potential workaround in this situation would be to have SPIA on one CPU subsystem, while SPIB is on the other. Since each CPU subsystem has it's own CLA and DMA, you can use each independently.

    Thanks,
    Mark
  • 0 in reply to Mark Labbato
    Prodigy 225 points
    Thank you so much for taking the time to confirm and provide a good alternative.
    Take care,
    Ryan