PINE64

Full Version: SPI DMA and toggling CS
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I'm having trouble with toggling CS pin when running SPI in DMA mode. 

It does not toggle/switch CS when if I keep supplying continuous DMA stream (on an interrupt send a next DMA). I would like it be able to specify that I want it switch/toggle CS once one DMA transfer is finished.

The only way to toggle CS is let the DMA channel close, but then re-opening it takes over 8 us and I need max 3.2us. I was able reduce it to 5.7us by re-writing SDK provided libraries but to go any further I need to replace ROM functions.

Any suggestions? Thank you very much.
(12-29-2016, 09:08 PM)kissste Wrote: [ -> ]I'm having trouble with toggling CS pin when running SPI in DMA mode. 

It does not toggle/switch CS when if I keep supplying continuous DMA stream (on an interrupt send a next DMA). I would like it be able to specify that I want it switch/toggle CS once one DMA transfer is finished.

The only way to toggle CS is let the DMA channel close, but then re-opening it takes over 8 us and I need max 3.2us. I was able reduce it to 5.7us by re-writing SDK provided libraries but to go any further I need to replace ROM functions.

Any suggestions? Thank you very much.
I don't have good answer and already post your question to Realtek engineer. hopefully they have a good answer.