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dmar & dmat bits

Posted on September 08, 2009 at 11:57

dmar & dmat bits

1 REPLY 1
Posted on May 17, 2011 at 13:23

Hello,

I have been using DMA for both Rx and Tx without any problems for some time. During USART initialization both DMAR and DMAT bits are set and do not change for the rest of my application.

However the user manual says I should reset them after each DMA transfer but it does not explains why. I also changed the code to work that way but in the end no change. That works too. However I had to enable xfer complete interrupts which I dont need in fact.

Can someone tell why we should reset DMAR and DMAT bits after each transfer. It is easily doable for tx but not easy for rx as we dont know when a byte would come. Also it adds two unnecessary interrupts.

I appreciate any input...

Kerem