Accumulator value changed after ISR execution (DSP C5402)

Youssef Lyoussfi

Hello,

When i want to use the acumulator A after the execution of timer interrupt i found different value then the value before interrupt execution.

This is my ISR function :

; Timer 0 Interrupt routine
IntTimer0:
push(AR0)
AR0 = #Timer0Counter
*AR0 = *AR0 - #1
AR0 = pop()
return_enable

There is no use of accumulators in ISR !!!

Sincerly

Youssef

over 12 years ago

0 Bill Finger over 12 years ago

Genius 3735 points

What does 'return_enable' do?

Why don't you single-step through the ISR with your debugger and figure out which instruction changes the accumulator?

Regards,

Bill

0 Youssef Lyoussfi over 12 years ago in reply to Bill Finger

Intellectual 390 points

Hello Bill,

return_enable do a return from the ISR with enabling the Interrupt.

The problem is is i execute my program Step by Step it works but is i execute is normally the value changes.

Best regards

Youssef

0 Bill Finger over 12 years ago in reply to Youssef Lyoussfi

Genius 3735 points

Youssef,

Well, the accumulator isn't changing itself. Is this your only ISR? Perhaps another interrupt is happening that changes it. When you single step interrupts are disabled.

Regards,

Bill

0 Youssef Lyoussfi over 12 years ago in reply to Bill Finger

Intellectual 390 points

Thanks Bill for responding,

I'm Sure that it's the only ISR in my program.

Is there any other interrupt that could be calling a built in ISR ?

Best regards

Youssef

0 Bill Finger over 12 years ago in reply to Youssef Lyoussfi

Genius 3735 points

To my knowledge there are no 'built in ISRs'. You should be able to tell which interrupts are enabled by looking at the interrupt enable register. There might be an NMI on this platform; if so you should find what address it is mapped to and see if it is being called by sticking a breakpoint there.

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Accumulator value changed after ISR execution (DSP C5402)