I have GPDMA working on STM32U5 with a circular buffer. However, when I add a GPDMA "trigger" to the setup, the DMA no longer works.
GPDMA1_C2TR2.TRIGPOL=2
GPDMA1_C2TR2.TRIGSEL=11
GPDMA1_C2TR2.TRIGM=3
LPTIM1 setup to clock away at a 50% duty cycle.
What I would expect to see is the DMA transfer working slower than normal based on the ARR period of LPTIM1. But, the above combination of values along with a few variations just results in stopping the DMA.
What would be helpful is some example application running on a nucleo board which makes use of a GPDMA driven device where both a DMA request and a DMA trigger are being used. (Documentation seems to be lacking. They do describe what the triggers are and from what I can tell how they should work, but because it is not working some vital clue is missing or hidden.)
