Alan Goetzelmann

Coldfire MCF5235 Interrupts

Discussion created by Alan Goetzelmann on May 26, 2006
Latest reply on May 31, 2006 by Michael Norman

I have a question about interrupts on a MCF5235 Coldfire part.

I am using two interrupts, timer0 and IRQ1. IRQ1 is configured for level sensitive operation.

Timer0 has a higher priority level then IRQ1.

When IRQ1 pin goes low, and interrupt triggers and all is fine,

Occasionally during the IRQ1 service routine the timer0 interrupt occurs.

When the timer0 ISR is done it appears that the IRQ1 interrupt is retriggered.

Looking at the stack frame you will see two occurrences of the IRQ1 ISR.

During this time the IRQ1 pin is still low.

Is this normal?

Am I crazy?

How do I stop the IRQ1 from retriggering?

I do not plan on changing IRQ1 to an edge sensitive interrupt.

Is there a good application note on the Interrupt controller?

Any Ideas?

 

Thanks Alan

 

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