Connect DMA channel to TIM3_TRIG request

onegray · ‎2016-03-21

Posted on March 21, 2016 at 17:01

I am playing with STM32F030 device. Accordingly to ''DMA request mapping'' table (RM0091), it should be possible to use DMA1_Channel4 for TIM3_TRIG request, but I have some doubt how to do it in the right way.

What I am trying, but without success:

// Using ''Update'' event as a TIM3 trigger output

TIM_SelectOutputTrigger(TIM3, TIM_TRGOSource_Update);

// Setting TIM_DMA_Trigger as DMA source

TIM_DMACmd(TIM3, TIM_DMA_Trigger, ENABLE);

I believe the other timer and DMA initialisation is correct. I was able to use DMA1_Channel3 with TIM3_UP request - it works as expected. Now I want to use DMA1_Channel4 because I need two DMA channels working upon TIM3 Update event.

#tim_dma_trigger

waclawek.jan · ‎2016-03-21

Posted on March 21, 2016 at 22:21

While the RMs are far from being crystal clear in this respect, I believe that the Trigger interrupt/DMA source refers to TRGI rather than TRGO.

JW