TMS320F280039C: C28x interrupts: When is INTM cleared

Andreas Stolze

Part Number: TMS320F280039C

Hi all,

I was wondering when INTM is cleared. I am talking about the normal use case, not manually clearing it for nested interrupts or similar.

In the documentation I can see that INTM is set automatically when entering an interrupt:

I could not find any information about when this is automatically cleared. I don't clear it explicitly in the interrupt code.

Is it maybe cleared by the IRET command?

Thanks
Andreas

over 2 years ago

+1 Vince over 2 years ago

TI__Mastermind 19795 points

Hi Andreas,

Thanks for your question. The hardware actually restores INTM to its previous state upon exit of an ISR. Here's a table from the Interrupt Nesting page that explains a NORMAL interrupt entry and exit. So this table applies to normal ISR cases, WITHOUT nesting:

Here's the page it came from:

https://software-dl.ti.com/C2000/docs/c28x_interrupt_nesting/html/index.html

Regards,

Vince

0 Andreas Stolze over 2 years ago in reply to Vince

Prodigy 80 points

Thanks for clearing this up.

However, I would like to find this kind of information in the documentation as well, at least a reference to it. The process how the interrupt is entered is already explained, why not add the exit behaviour as well?

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TMS320F280039C: C28x interrupts: When is INTM cleared