detachInterruptVector?

[duff]

I was wondering if there is any plans to implement detachInterruptVector routine?

Why I ask is if i claim a certain ISR ( attachInterruptVector(IRQ_NUMBER_t ira, void (*function)(void)); ) and I then want to pass it back ( detachInterruptVector(IRQ_NUMBER_t ira, void (*function)(void)); ) to whatever the core defaults too. I guess i can do this myself if not.

 

[PaulStoffregen]

I'll put this on my TO-DO list. I simply didn't think of it earlier.

 

[MichaelT]

I found myself needing a detactInterruptVector - has a fix been found yet (in the 9 years since the last post!)? If not, what would be the steps to do it? I'd like to do this for the QTM timer on Teensy 4.1

 

[jmarsh]

Most things don't have default ISRs, you can use NVIC_DISABLE_IRQ() to make sure it won't be triggered any more.

 

[MichaelT]

How does that relate to handling multiple interrupt functions attached non-simultaneously to the timer? I'd like to attach one ISR "my_isr_1" using attachInterruptVector(QTIMER1,my_isr_1);, then at some later point replace that with "my_isr_2".

If a second call of attachInterruptVector overwrites the first one, then I could imagine the following would work (which I have actually confirmed is working). But maybe someone can explain what is going on under the hood.

attachInterruptVector(QTIMER1,my_isr_1);
// start timer by changing QTM registers
NVIC_ENABLE_IRQ(IRQ_QTIMER1);
...

NVIC_DISABLE_IRQ(QTIMER1);
// followed by changing QTM registers to stop timer
...

attachInterruptVector(QTIMER1,my_isr_2);
// restart timer by changing registers
NVIC_ENABLE_IRQ(IRQ_QTIMER1);
...

 

[jmarsh]

attachInterruptVector does indeed overwrite whatever function was already set.

static inline void attachInterruptVector(enum IRQ_NUMBER_t irq, void (*function)(void)) { _VectorsRam[irq + 16] = function; asm volatile("": : :"memory"); }

All possible ISRs are just elements in the _VectorsRam array.