• State Resolved
  • Locked Locked
  • Replies 2 replies
  • Subscribers 29 subscribers
  • Views 397 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

RM57L843: Mib-SPI with DMA support

Gunter Schmer
Genius 14202 points
Part Number: RM57L843
Other Parts Discussed in Thread: TCAN4550, HALCOGEN

Hi,

a customer is using a TCAN4550 with the RM57L843 over Mib-SPI. As part of that interface multiple Transfer Groups TGs with buffers get initialized and enabled. When the Mib-SPI is complete, currently the CPU is used to read out the data. But we would like to use the DMA instead.

Are there good examples for usage of Mib-SPI with DMA?

Specific questions about the DMA:

  • Can the DMA read 4 16-bit Mib-SPI buffers, extract only 8-bits of data from each, and then write the data as big endian into a byte array?
  • Can the DMA repeat the above operation over multiple buffers, effectively reading all of the buffers within a transfer group?
  • Does the Mib-SPI have any built-in hooks with the DMA to read/write data to/from the Mib-SPI buffers?

Thanks!

--Gunter

  • 0
    TI__Mastermind 49120 points

    Hi Gunter,

    HALCoGen includes an example for using DMA with MibSPI. It is a basic example for TX DMA using internal loop-back mode, but it serves to demonstrate triggering the DMA using a TX event.

    As for the specific DMA questions:

    • Can the DMA read 4 16-bit Mib-SPI buffers, extract only 8-bits of data from each, and then write the data as big endian into a byte array?
      • Yes, this is certainly possible. The DMA controller supports flexible byte offsets on the source/destination indexes, which can be used to "manage" the read and write operations.
    • Can the DMA repeat the above operation over multiple buffers, effectively reading all of the buffers within a transfer group?
      • The application can define the required trigger event and configure it to transfer a block or frame per each trigger. The number of elements per frame and number of frames per block are configurable as well.
    • Does the Mib-SPI have any built-in hooks with the DMA to read/write data to/from the Mib-SPI buffers?
      • Yes, the connection between DMA request number and the specific MibSPI instance is defined in the datasheet.

    Regards,

    Sunil

  • 0 in reply to Sunil Oak
    TI__Mastermind 49120 points

    Gunter,

    Are there any questions about my comments in the previous post? Was the customer able to configure the MibSPI and DMA to do what was required?

    Regards, Sunil