Using DMA with UART, with and without FIFO buffer

panchogalactico — Wed, 04 Jul 2012 03:06:05 GMT

Hi. I´m having problems with the DMA. I use a k20 MCU, clocked to 72MHz.

I want to receive 8 bytes in the UART0, filling the RX buffer FIFO, and then move them to a int mem[8] array.

I can´t make it work. My question is about UART0_D register, because, as I understand, I have to read 8 successive times that register to get the 8 bytes, and the DMA machine increment the source pointer automatically after every read. So, How do I do it?. Can i force the DMA machine to keep the source pointer pointing to UART0_D while the destiny pointer incrementing automatically?

Actually, if I can force the DMA machine to do that, I guess that I didn't need to use the RX buffer FIFO.

Any ideas?

sorry for my poor english.

Re: Using DMA with UART, with and without FIFO buffer

panchogalactico — Wed, 04 Jul 2012 03:56:29 GMT

I make it work, so I post here the answer.

If I set DMA_TCDn_SOFF = 0 , then the source pointer wont increment.

very easy actually.

topic Using DMA with UART, with and without FIFO buffer in Kinetis Microcontrollers

Using DMA with UART, with and without FIFO buffer

Re: Using DMA with UART, with and without FIFO buffer