I am using an ADSP-21479. I have multiple interrupts in use. Interrupts are NOT nested.
I am toggling a pin inside one of the ISRs to time how long it takes to execute. I put the pin high as the first instruction in the ISR and then I put the pin low as the last instruction in the ISR.
I look at the state of the pin using an oscilloscope and I see that the pin can be high any where from 0.2 usec to as much as 7 usec. What can cause such a large timing difference? If interrupts are not nested what could possibly be causing the time spent in the ISR to be so drastically different each time it executes?