Hi, I’m running 9.0.0 on an ARM CM4. I’m using SysTick at 1000 Hz.
I can see that xPortSysTickHandler() gets called precisely every 1000 usec.
The problem I’m seeing is that my timer callback function gets called every 1075 usec (worse if I use tickless).
I understand that FreeRTOS like any OS has a processing delay, but that should only mean that the first call to my callback is delayed. If the processing delay is constant, the interval between all the following calls to my callback should still be 1 ms, right (I have no other timers in my system)?
The precise code and values doesn’t matter at this time, I’m trying to understand theoretically why there is a cumulative delay presented to timer callbacks.