UART DMA Rx, IDLE interrupt is triggered, but doesn't look correctly.

LWei.1 · ‎2020-10-03

Hi,

I am trying to use DMA to realize uncertain length uart message receiving on STM32H745i-DISCO board (on core CM7). My idea is to used IDLE interrupt and then disable the DMA_stream, get the NDTR register and abort the transfer to trigger the DMA TC interrrupt to get the data. I send a string at once, but looks like everytime the IDLE interrupt triggered after receive the first byte. And the the UART_DMAReceiveCplt() function never get chance to be called. Can anyone help me with that?

Thanks!

LWei.1 · ‎2020-10-09

I moved the code from CM7 to CM4, it works. I think it shall be related to DMA_MEM accessibility issue for M7 core. I will try to figure out it by myself.

Also, Tilen Majerle's github repo also used IDLE interrupt instead of RTO interrupt.

View solution in original post

LWei.1 · ‎2020-10-06

Can anyone give me some hint what is wrong with my implementation? Thanks!

Pavel A. · ‎2020-10-06

IMHO for this better to use RTO interrupt (RX timeout) rather than IDLE.

Example can be found in Tilen Majerle's github repo.

-- pa

LWei.1 · ‎2020-10-09

I moved the code from CM7 to CM4, it works. I think it shall be related to DMA_MEM accessibility issue for M7 core. I will try to figure out it by myself.

Also, Tilen Majerle's github repo also used IDLE interrupt instead of RTO interrupt.