DMA USART polling RX

michele23 · ‎2015-09-30

Posted on September 30, 2015 at 15:39

Hello,

im using TMS32F071RB.

I would like to use USART peripheral in DMA without using interrupt, but polling at TCIF.

Is that possible?

Thanks,

M

#dma-usart

Tesla DeLorean · ‎2015-09-30

Posted on September 30, 2015 at 18:37

Is that possible?

I would suspect so, I'd probably look at HT and TC, to avoid potential race issues as stuff gets over written, but yes.

Might want to work on that dyslexia, it looks like you're using a TI part.

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jpeacock · ‎2015-09-30

Posted on September 30, 2015 at 21:03

No reason you have to use an in interrupt as long as there's nothing else for the CPU to do. You may have a problem with variable length incoming messages...how will you know in advance the exact size for the DMA, and what happens if you lose a character or there's a framing/overrun/parity error? A TC loop will spin forever.

For DMA TX no problem since you always know the message length.

Jack Peacock

michele23 · ‎2015-10-01

Posted on October 01, 2015 at 14:03

Frame lenght is going to be constant.

I plan to use LIN mode to recognize EndOfFrame, in case i loose some character.