This project is for testing and debugging the output compare toggle mode of TIM1 in the STM32G0 series of microcontroller.
Toggle mode is set with OCxM=0011 for x=1 to 4 in the TIM1_CCMR1 and TIM1_CCMR2 registers.
Interrupts are used to modify the value in the Capture/Compare Register to create
staggered 100us pulses on each of TIM1_CH1 through TIM1_CH4.
The timing was validated using an oscilloscope.
I confirmed that the toggle mode really does toggle. It does not start in a fixed state on each count up cycle. This could be a problem if the timer is stopped as part of a safety fault and later restarted.
I added a saftey check by reading the GPIO pin in the interrupts.
If the TIM1_CHx output is in the wrong state, a polarity_fault flag is set for the main-line code to handle.
MIT license