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Altera_Forum's avatar
Altera_Forum
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20 years ago

DSR not called

Dear Forum readers I've been scrathing my head for some time over this. I have a custom board that gives me a periodic interrupt. I've written a ISR- DSR handler pair and they wo...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
20 years ago

Hi Mike

If you use the ISR/DSR setup you can do it that way, and there's no problem. But if you have a fast lowlevel interrupt you cannot aford waiting for the DSR to reenable the irq.

I do not claim that the approach is an error just that each irq eats 80 bytes of stack and that you'll have to allow for this mem usage in each stack in every thread.

If you have interrupts comming back to back, which is quite normal, the stackpointer will not be restored between each of them and eventually you'll crash.