I am using a tiny26 & trying to use pin change interrupts on PA6.
I set GIMSK to $20 (PCIE1=1) & use the SEI instruction.
I am not getting into the interrupt routine for some reason. I tried setting the ACD bit in ACSR to zero as well (should be zero from power up)---no luck.
I am using the proper vector.
Now I DO seem to get into it at intiailization when I happen to be toggling some other I/O lines (I ultimately will check the ISR for PA6 being low & filter out these intruders)
I set DDRA to give PA6 as an input (bit=0)
I set Porta pa6 bit to both 1 & 0 with no difference
Now I do have some timer interrupts going on at the same time. I save & restore the SREG & do an RETI & this ISR seems to be fine.
Question: Will my timer ISR cause a pin change interrupt to be "lost"/missed
I do not do anything with the GIFR -PCIFflag register at all--to my understanding I don't need to fool with it????
what is consideed a pin change? I am assuming a single pin changing (PA6) will be enough to trigger the interrupt. The other lines may or may not be toggling (I plan to filter them out, since I want to execute the interrupt only when PA6 is going low).
For my testing I am tapping a wire to PA6 between high (5V) & low (gnd). Note it is likely this is happening during my timer ISR interrupt which happens at a fast rate. I also tried enabling interrupts within the timer ISR (using SEI)--again no luck.