STM32L4 UART+DMA

ChrisH · ‎2017-01-10

Posted on January 10, 2017 at 20:37

I have an RTOS app running with few tasks though I don't think it matters if you use OS or not anyway. Basically every now and then I get random errors like FE (framing error), ORE (overrun error), NF (noise flag set). There are two UARTS that have running DMA channels connected to both RXes in circular mode. I had a previous configuration that favoured one UART over the other giving it higher DMA priority. Correct me if I'm wrong, but could this potentially be an issue for the errors?

ChrisH · ‎2017-02-07

Posted on February 07, 2017 at 22:17

I don't think DMA priorities matter when you change them between UARTs I think you can have them on the same priority unless you use some crazy baudrate. If you have 6 UARTS and want to use just interrupt based method It will be probably quite painful to deal with. My logic with stm32 is always enable RX DMA in Circullar for every UART I use, for TX it's not necessary and dependent on particular application.