hard20 pts · first answer countsperformanceinterrupts

Jitter in a control loop ISR

A 20 kHz motor-control ISR on a 168 MHz MCU has varying execution time. The jitter disappears when the ISR is placed in RAM. What explains this?

A.RAM code ignores interrupt prioritiesB.The ISR was being preempted by the RTOS tickC.Running from flash needs wait states, and prefetch or cache misses make timing vary; RAM has zero wait statesD.Flash code runs in a lower power mode

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