AnsweredAssumed Answered

Timing an ISR on ADSP-21479

Question asked by pozzi on Jun 26, 2012
Latest reply on Jun 28, 2012 by pozzi

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?


Thank you,