I have come across a rather weird problem and would like to get some direction.
I am using STM32F756 nucleo board. I set ADC1 to trigger by TIM1 (the complete project uses some other peripherals). TIM1 is set as PWM generation. All these are set using CubeMX in CubeIDE. In ADC setup, continuous DMA request is enabled, continuous conversion disabled. Trigger set to TIM1 update event (also tried with external trigger and shorting TIM1 output to EXTI pin with jumper). ADC1-DMA is set to circular mode. In the code, I start ADC with "HAL_ADC_StartDMA" before starting the timer. To start the timer, I copied "HAL_TIM_StartPWM" and made another method, let's say, "Private_TIM_StartPWM" which is almost identical to the HAL method except it doesn't have the "__HAL_TIM_ENABLE" call at the end. So, when calling this method, TIM1 is set up for PWM generation but the counter remains idle and will be enabled separately later.
Now onto the problem, in the code, before TIM1 can be enabled, the DMA transfer complete interrupt is fired. I have checked that the SR register has only TCIF flag set in the interrupt. However, checking the timer output with oscilloscope, the timer is not outputting any pulse, so, the ADC should not be triggering at all. When I checked the DMA buffer, there is no data there.
I set up a separate minimal project with only ADC1 and TIM1 set the same way to reproduce the problem but in this case, it works fine as expected. So, back in my main project, I debugged with breakpoint in every IRQHandler (only 4) and the DMA transfer complete interrupt is the first one being fired, so, it probably is not a case of another interrupt messing with things. I have repeatedly debugged the interrupt, it is always only TCIF flag, no PWM in timer output, no data in buffer memory.
I am quite stumped as to what is causing this and would like some guidance as to what should I look into. Thank you for your precious time.
