Hi, We are facing issue with the execution of PWM ISR timing. The PWM timing on HW pin is fine. Isuue observed the entry time of ISR have a timing distrubance periodic. The project is built with freeRTOS. without RTOS there is no jitter.
To reduce the complexity, created a simple freeRTOS project with etPWM1 configured with center aligned up-down counter of 40 uSec period. RTOS configured with ony one task, which will update 50% dutycycle of PWM. The PWM ISR is configured with ZERO count event. Measurement of ISR period is done with 1. toggle gio and use the oscilloscope 2. Use RTI 1 counter to capture the period.
Attahed the scope result and analysis of memory capture of the RTI counter.
We have tried to modify the interrupt priorities of RTI 0 and etPWM 1, still have the jitter. We have observed the jitter is periodic with 60 mSec.
Tried by removing the etPWM1 and use only RTI 1 interrupt and measure the RTI 1 ISR period. This measurement also show the jitter with 60mSec period.
I have attached captures of the scope and spreadsheet aswell as my project.
Please help me what could be the issue here.
