Problem with PSOC5 DMA - Forums Re: Problem with PSOC5 DMA
  • PSoC5 ES1 has a silicon bug wherein the DMA chain would not terminate when the next_TD parameter is set to DMA_INVALID_TD.  This will be fixed in next revision of Silicon.

    • WorkAround: The TD chain termination can be hence achieved by using another TD chained to the original TD. This TD needs to have destination address  DMAC_TDMEM[tdHandle].TD0[2]. The source address should be an SRAM location where the value  0xFF is stored, it could just be an 8 bit variable. Note that the tdHandle parameter above will be the value that was obtained eariler using CyDmaTdAllocate() API.

    Let us know if this works.

    Mon, 16 May 2011 05:23:21 -0600
    Re: Problem with PSOC5 DMA I've tryed the value oxFE but I'm getting only one interruption, after that "CyDmaChEnable(DMA_PWM_Chan, 1);" has no effect.

    In the mean time I'm using my configuration, then I make "CyDmaChDisable(DMA_PWM_Chan);" in the DMA interruption routine, this stops the DMA. This is nos actually a problem because I have some time between two DMA access, then, when I need again, I call "CyDmaChEnable".

    Mon, 16 May 2011 03:33:05 -0600
    Re: Problem with PSOC5 DMA Could you replace the DMA_INVALID_TD parameter with a value 0xFE and try .

    Fri, 13 May 2011 11:03:09 -0600
    Re: Problem with PSOC5 DMA I think your code should do what you want - don't know why it doesn't work. One thing you could do is to enable the termination output of the DMA, and use it to stop the timer. That way you don't depend on the exact configuration of the DMA.

    Thu, 12 May 2011 13:37:40 -0600
    Re: Problem with PSOC5 DMA I've connected the drq of DMA to the TC output of a timer, the idea is to transfer 16 bits (2 bytes) each timer period and stop after 1024 tranfer.

    Thu, 12 May 2011 06:41:12 -0600
    Re: Problem with PSOC5 DMA Do you want to transfer all 1024 values in one shot, or each value on request? AFAICS you set the DMA to transfer 2 bytes with each request - how have you wired up the DMA component to generate the burst request? The interrupt should be executed after all 1024 values have been transferred - and the configuration is set to end the DMA then.

    Thu, 12 May 2011 06:19:50 -0600