topic Re: DMA UART RECEIVE K60 in Kinetis Microcontrollers

DMA UART RECEIVE K60

mdrasool_yadwad — Fri, 23 Oct 2020 04:39:36 GMT

hello,

I am facing problems in receive. I want to receive 4 bytes and store in the buffer but the buffer is loaded with same value. below i have written my code please go through it .

//Receive Function

{
DMA_SADDR_REG(dmach , ch) =0;

DMA_SADDR_REG(dmach , ch)|= DMA_SADDR_SADDR(0x4006B007); // CONFIGURING SOURCE ADDRESS
DMA_SOFF_REG(dmach,ch) =0;

DMA_ATTR_REG(dmach , ch) = (DMA_ATTR_SSIZE(0) | DMA_ATTR_DSIZE(0)); //CONFIGURING SOURCE ADDRESS SIZE

DMA_NBYTES_MLNO_REG(dmach , ch) = 0;

DMA_NBYTES_MLNO_REG(dmach , ch)|= (DMA_NBYTES_MLNO_NBYTES(0x04));
DMA_DADDR_REG(dmach , ch) = 0;
DMA_DADDR_REG(dmach , ch) |= DMA_DADDR_DADDR(val); //CONFIGURING DESTINATION ADDRESS ADDRESS

DMA_DOFF_REG(dmach , ch) = DMA_DOFF_DOFF(0x01);

DMA_BITER_ELINKNO_REG(dmach , ch) =0;
DMA_BITER_ELINKNO_REG(dmach , ch) = DMA_BITER_ELINKNO_BITER(0x4); //STARTING MAJOR ITERATION COUNT
DMA_CITER_ELINKNO_REG(dmach , ch) =0;
DMA_CITER_ELINKNO_REG(dmach , ch) = DMA_CITER_ELINKNO_CITER(0x4); // CURRENT MAJOR ITERATION COUNT

DMA_SERQ |= DMA_SERQ_SERQ_MASK;

DMA_CSR_REG(dmach , ch) = DMA_CSR_START_MASK; // START THE DMA

}

Re: DMA UART RECEIVE K60

mjbcswitzerland — Fri, 23 Oct 2020 09:12:47 GMT

It looks like you are triggering the DMA using the software method which makes it copy the Rx data immediately and therefore it is is not transferring received data but instead just the value that happens to be in the buffer.

Have you set up the DMUX to trigger on Rx data?

Regards

Mark
[uTasker project developer for Kinetis and i.MX RT]
Contact me by personal message or on the uTasker web site to discuss professional training, solutions to problems or product development requirements

Re: DMA UART RECEIVE K60

mdrasool_yadwad — Mon, 26 Oct 2020 03:35:21 GMT

Yes I have DMUX to trigger on Rx data. But i am getting same data again and again. Don't know to do it i am really confused and struck in this.