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CppiDmaGetINTD0Status funciton in the usb_dev_msc

uitytur
Prodigy 215 points

hi..

I am using am335x Starterware2.00.00.7 -> usb_dev_msc.

In file cppi41dma.c ,  CppiDmaGetINTD0Status funciton

 

' intdReg0 = HWREG(usbInstance->otgBaseAddress + CPDMA_INTD_0_REGISTER); '

This Reg Value is '0x47400000 + 0x3200' .  I can't find this Vaule in the AM335x TRM (SPRUH73G)

 

Waiting for the response ,Thank

 

 

 

  • 0
    TI__Intellectual 1640 points

    Hi Lee,

    The intention of the function CppiDmaGetINTDStatus () is to clear the  RX_SOP_STARVATION interrupt. The register offset  does not appear in AM335x  TRM as this is a port from a legacy code running on a different processor and Am335x uses a different set of registers to do the same  . Please note that this function is not working. Could you please refer the following USBSS Registers - 

    IRQSTATRAW 
    IRQSTAT -- reports status of enabled interrupts
    IRQENABLER  - enable or disable interrupts
    IRQCLEARR 

    Also , please use the DM814x TRM ( freely downloadable) for getting the offsets and access to all registers.  

  • 0 in reply to Vineeth Balan
    Intellectual 530 points

    Hi,

    Can anyone please explain me why rx_sop_starvation condition occurs? In the documentation it says "0 rx_sop_starvation Interrupt enable when queue manager cannot allocate an Rx buffer at the start of a packet." This explanation is not sufficient. Why do I get this event and how can I avoid it. I have a 512 byte rx that ends with this bit set even though previously in my code(driver for a proprietary rtos) there were numerous successful 512 bytes rx transactions using CPPI DMA. Thanks.

    Regards,

    Mughees Ahmed Chohan

  • 0 in reply to Mughees Chohan
    TI__Intellectual 1640 points

    Hi Mughees 

    An Rx SOP starvation interrupt occurs when there is an OUT (host sends data to device) transfer on one of the endpoints, and the CPPI dma finds that there are no free buffers hooked up to receive that data sent by the host.

    You would need to open a new thread with the same question if you need more help regarding this.

     

  • 0 in reply to Vineeth Balan
    Intellectual 530 points

    Hi Vineeth,

    Thanks a lot for your reply. I have made a new thread at http://e2e.ti.com/support/dsp/davinci_digital_media_processors/f/716/t/300421.aspx. Please can you have a look at my reply on that. Thanks once again.

    Regards,

    Mughees Ahmed Chohan