DT-INTs What's legal in an INT handler?

[Michael Wakileh]

? toggle command is only good for port pins ?

[circuitpro]

Oh my gosh, you're right! I don't know why I thought that would work for a bit. That fixed it.

THANKS Michael.

[Bruce]

Bruce, could you please explain your comment to me? I would think that PBP knows what bank it is in, and keeps track of that - even in an interrupt handler. Is that not true?
And what constitutes "outside the interrupt handler"? Must all the handler code be placed between the INT entry point and the INT_RETURN?
I have to admit, I have violated your "rule" and it hasn't caused problems. Am I lucky?
Please explain.
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Charles Linquist

Hi Charles,

Would be happy to answer if you could point me to the inital post...

[Charles Linquis]

This is a cut-and-paste from post #2 above.





With DT_INTS using a PBP type interrupt, pretty much anything goes. I.E. use as many
PBP instructions as you like in the int handler.

That's the really cool part of using DTs' int program. He's done all the work for you.

Just don't GOSUB outside the interrupt handler - or it will go-like-splat...
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[circuitpro]

I wanted to clarify a point just to possibly help somebody else...

Unfortunately, TOGGLE does work to change the state of a BIT variable, even though this is an incorrect use of the command! It also quite possibly clobbers some other unsuspecting variable, in this case a LONG. It would be nice if the compiler would flag it, but it doesn't so BEWARE!!

Thanks again, Michael.

[Bruce]

Hi Charles,

What I meant was -- you don't want to jump outside an interrupt handler routine - without
returning to it.

I.E. if you GOSUB outside the interrupt routine, and don't re-enter it before your return, you might
experience major problems.

DT_INTS needs to exit from DT_INTS. If you jump outside of this routine, and try to return
from the interrupt on-your-own, you're going to have a problem.

Exit from an interruppt requires a lot of regitsers to be restored.

If you jump outside of the int routine, and return on-your-own, you will for sure see a problem.

[aratti]

I.E. if you GOSUB outside the interrupt routine, and don't re-enter it before your return, you might
experience major problems.

------------ DT Interrupt handler --------
Get_Byte:

do something here

If black then gosub apples
If withe then gosub peach

@ return


apples:
do something
return

peach:
do something
return

Bruce, can you please explain better your statement? from what you said, I understand that the above example code could give problems, while I am using this type of jump out of the interrupt handler, quite often and I never experienced any problem.

Al.