Disable Global Interrupt

[Franck26]

Hello everybody,

I was wondering:
If I Disable the global interrupt for a while and if some interrupts event append during this time, am I going to have these interrupt event when I will enable the global interrupt?

Example:
- enable global interrupt,
- Enable Timer0 overflow interrupt,
- Prog is running,

- Disable global interrupt,

- Prog is running,
- Timer0 overflow append.
- Prog is running,

- Enable global interrupt,
- Am I going to have a Tmer0 overflow interrupt immediately here?
- Prog running.

Thanks for your help.

[Ttelmah]

Basically, yes.
The interrupt dispatcher is called, if the following conditions are all met:
1) Global interrupt enable is true.
2) Individual interrupt enable is true.
3) Corresponding individual interrupt flag is set.
When you set '1', if the other two things are already true, the interrupt will be called.

The flags latch, so if you don't want interrupts that have occured in the interim to be called, you need to clear the corresponding interrupt bit (clear_interrupts). Beware also though, that some flags (INT_RDE for example), are also dependant on a further hardware event (the buffer containing a character), so this itself needs to be cleared, or the flag will remain set.

Best Wishes

[Franck26]

Hi Ttelmah,

Thanks for your answer, it's what I wanted to know.

Franck.