Interrupts in the C18 3.0 software

[JohnC]

I'm reading interrupts.c and I notice that Initialize_Int_N() sets a register (I think it's a register) to 0, which the comment says disables the interrupt.

Why is this done? Should I change that to a 1? If so, it seems like it would make more sense to have a Set_Interrupt_N(int) function so that the interrupts can be turned on and off.

Anyway, why isn't this defaulted to 1 since users have to uncomment the ENABLE_INT_N macros for the function to "exist" in the first place? Maybe I'm just confused?

[interfect]

Could it be that the register being 1 disables the interrupt, and the register being 0 would thus enable it? I haven't seen the code, so I don't really know what I'm talking about, but that would make sense.

Or maybe you're supposed to enable it later.

[Kevin Watson]

Why is this done? Leaving it at zero allows you to use the interrupt hardware in polled mode, which is nice because you don't need to write an interrupt service routine.

-Kevin

[JohnC]

Leaving it at zero allows you to use the interrupt hardware in polled mode, which is nice because you don't need to write an interrupt service routine.

-Kevin

I'm confused. How does that accomplish anything? How do you do something with the interrupt without an ISR?

[Kevin Watson]

I'm confused. How does that accomplish anything? How do you do something with the interrupt without an ISR?You poll the interrupt flag bit and wait for it to change.

-Kevin