2008-03-04 09:28:21 DMA_DONE bit of DMA

kanal kannan (INDIA)

Message: 52027 Hi all,

I'm using BF561 ezkit lite and i've incorporated the PPI0 driver into the kernel. I've 4 frame buffers to fill video data in circular fashion, when i run the application, the PPI0 fills the video data in 2 buffers and the descriptor pointer is not pointing to my 3rd & 4th buffer. After analysis i found that the DMA_DONE bit of DMA status register is enabled for data transfer is not getting cleared. Data is getting filled in the initial 2 buffers and after which when ppi0 is disabled the registers & bits pertaining to ppi0 are reset to zero but whereas the DMA_DONE bit of DMA1_0_IRQ_STATUS register still remains uncleared due to which i'm not getting data in the adjacent buffers. What should i do to clear this bit after each dma transfer and also what should be done to point my DMA_DESC_POINTER to point to the next address location where my 3rd & 4th buffer are present.

any help in this regard is highly appreciated.

with regards

Kannan

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2008-03-13 10:00:50 Re: DMA_DONE bit of DMA

Robin Getz (UNITED STATES)

Message: 52453 Kannan:

Low level hardware questions are normally answered in the Hardware reference manuals - did you check with the BF561 manual?

Thanks

-Robin