On my '407 I am using TIM2 to trigger a series of ADC conversions. The connection between TIM2 and the ADCs is TRGO.
I have set up the time base for TIM2 to be 84MHz and TIM2 has no prescaler and a counter period of 21,000.
I expected that this would give me 84M/21K = 4000 conversions per second.
I seem to be getting closer to 117.
Is there a /32 stage on TRGO?
I can't find any documentation that describes the generation of TRGO. And since it bypasses the compare registers, the match criteria is hidden in the trigger controller section.