Hi
I used ICU model to sample PWM signal. It works perfect in the most of time, however, the sample result turns a 30% deviation when the sampled signal keeping the same.
The sample result soon became normal in next 2 or 3 sample cycle.
I use the ICU in a 10ms period task to get the sample result and report it in a 50ms period
below image shows the change of sampled PWM frequency. It sample a stable pwm signal with 100hz. vertical axis stand for frequency while horizontal stand for time.
my ICU configure is as below: