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MSP430F5528: Fail in merging DMA driver library of USB & SPI

Kenley
Intellectual 1805 points
Part Number: MSP430F5528


Hi team,

My customer is merging the USB app using DMA 0 and SPI slave using DMA 1 but the USB data communication does not seem to be working. However, the Windows Device Manager recognizes it. 

They would like confirm the following:

1. Which Channel of DMA that usbdma.c is using ? They are concerning maybe the usbdma.c is conflicting with their driver library.

2. Does the number of DMA usage change with the endpoint communication link ?

3. Currently, they are using one unit of DMA because they use HID devices in their application. Do they need more units of DMA when they use CDC devices ? Or will the USB protocol stack still use only DMA0? 

Thank you in advance.

Best regards,

Kenley

  • 0
    TI__Mastermind 30016 points

    Hi Kenley,

    For Q1:  DMA_CHANNEL_0, you can find this information in descriptors.c

    For Q2:  I don't find there are have special link:

    For Q3, I think DMA Channel 0/1/2 can support USB peripherals:

    Thanks!

    Best Regards

    Johnson

  • 0 in reply to Johnson He
    TI__Intellectual 1805 points

    Hi Johnson,

    Thank you for the prompt reply!

    For Q1, customer has developed their USB app driver library using DMA CH0, it means that it will get conflicted with the usbdma.c right ?

    In order to fix this, should we ask the customer to use DMA CH 2 for their USB app?

    Best regards,

    Kenley

  • +1 in reply to Kenley
    TI__Mastermind 30016 points

    Hi Kenly,

    In our example code, we use DMA CH0 for USB, thus if customer use our example for USB, I think this is OK.

    But if customer use another peripherals and USB lib, there will have some conflict issue for DAM channel.

    Thanks!

    Best Regards

    Johsnon

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