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TMS320F28379D: Data exchange between CLA1 and CLA2

HS FAE Germany
Mastermind 32500 points

Part Number: TMS320F28379D

Hello,
what possibilities are available to exchange data between CLA1 and CLA2?
- CLA1->CPU1.LSx->DMA1->GSxRAM->DMA2-CPU2.LSx->CLA2
- CLA1->MSG RAM1->DMA1->GSxRAM->DMA2-MSG RAM2->CLA2
Is it that complicated?

- Is it possible that CLA1 would send data over SPI to CLA2?
- Can an not used peripheral register (eg GPIO, McBSP) be misuse to exchange data?

Regards, Holger

  • 0
    TI__Mastermind 32995 points
    Hi Holger,

    The CLAs only have access to the message RAM between itself and its associated CPU, and have access to LS (Local Shared) RAM. It does not have access to GS (Global Shared) RAM or CPU1-CPU2 message RAM. Additionally, the DMAs only have access to GS RAMs and CPU1-CPU2 message RAMs.

    You can see this illustrated in the Data Sheet.

    Therefore, it appears you will not be able to get around using the CPUs to transfer the data.

    It is possible to transfer the data over SPI. But you will need to use 2 SPIs and use an external connection, since a single SPI can only be assigned to one CPU. Only one CPU can have access to a SPI module.

    Hope this helps!
    sal
  • 0 in reply to Sal Pezzino
    TI__Mastermind 32500 points
    Hello Sal,
    I think the DMA has also access to the CLA message RAM and LS RAM. So it would work w/o CPU.

    My question is more if you could misuse a peripheral register which you don't use like GPCDAT to exchange date from CLA1 to CLA2?

    Regards, Holger
  • 0 in reply to HS FAE Germany
    TI__Guru** 116081 points

    Hi Holger,

    Sal is right. DMA does not have access to CLA message RAM or LSx RAMs. Does any statement/figure in any document tells other way?

    Also if GPIO is not used (not selected as GPIO in pinmux)  then write to GPxDAT register from one master will not reflect into GPxDAT registers of other master so that also will not work.

    Regards,

    Vivek Singh