9 times out of 10, my program awakes fine (IOC interrupt related), but....

[cncmachineguy]

Hank, while I am no old hand, may I remind you there are things we can do- but shouldn't. Like bungee jump or sir jump. I guess this also includes gosubs. Btw, for he benefit of those reading, it's not limited to gosubing from DT_int, it's any interrupt.

Thanks for sharing Hank, we all learn from others mishaps.

[HankMcSpank]

Thanks bert :-)

Ok, I've removed all the gosubs from the interrupt routine, but I'm still getting erratic results...I kinda know what's not causing my PIC to go to sleep , but the workaround is ugly.

I think I'm hitting diffs with nested gosubs. Imagine this scenario (this is just high evel *not* my actual code - just to get my problem across)...

loop1:
if pattern = 2 then goto loop2
IF sleep_flag = 1 THEN GOTO SLEEP_ROUTINE
pause 10
gosub decrease duty
gosub select_LED1
pause 10
gosub increase_duty
goto loop1:
'
loop2:
if pattern = 1 then goto loop1
IF sleep_flag = 1 THEN GOTO SLEEP_ROUTINE
pause 10
gosub decrease duty
gosub select_LED2
pause 10
gosub increase_duty
goto loop2
'
SLEEP_ROUTINE:
debug "PIC off to sleep",13,10
pause 200
@sleep

' program continues here afteran IOC interrupt....
pause 100
debug "PIC awake",13,10

IOC_Int:
@ INT_DISABLE  IOC_INT

if sleep_flag = 1 then ' if we wake from asleep, this flag will be set still need to clear it & retun to the main program
sleep_flag = 0
goto INTERRUPT_END
endif

LOOP3:
        IF SW1 = 0 THEN 
        COUNT3 = COUNT3+1
        IF COUNT3 >300 THEN      'if Sw1 held for 300mS then set sleep_flag
        SLEEP_FLAG =1 
        goto INTERRUPT_END
        ENDIF
        pause 1 
        GOTO LOOP3
        ENDIF

if pattern <2 then    pattern=pattern+1  'cycle between pattern1 & pattern 2
else
pattern=1
endif

INTERRUPT_END:
COUNT3 =0  
while sw1=0
wend
PAUSE 180 
IOCAF = 0         'CLEAR THE INTERRUPT FLAG
@ INT_ENABLE  IOC_INT
'**************
@ INT_RETURN

It seems the interrupt routine (or program!) doesn't like the highlighted Gosubs in the loop1 & loop2 - if I remove the gosubs & instead locate the actual code contents of the gosubs in each loop - then everything is dandy (i.e. the PIC always goes to sleep & awakes fine) , but if I have gosubs in those two main loops - it looks like the interrupt routine (or some other aspect of my program) doesn't return to the main two loops & then trap the sleep_flag being hit! (the problem here is that by not using gosubs I run out of program space *very* quickly!)

What am I missing here?

[HenrikOlsson]

Hi,
First, I don't understand why you shouldn't (can't) be able to use GOSUB inside or outside of a DT-INTS ISR as long as you RETURN (as you should with ANY GOSUB), anyone care to elaborate on the reason you say you should never do that? Yes, the stack is limited, so you need to makes sure it doesn't overflow if you happen to get an interrupt when you're already into x nested GOSUBS but as far as I can see it should work.

Hank, I'm not syaing I have a solution for you but is seems to me that your program can "fall thru" into the ISR by itself. It wakes up, DT-Ints trips and jumps to the ISR, the ISR runs and the then it returns to where it woke up, which is right before the ISR so the ISR runs again. It hits the @INT_RETURN (by the way, there seems to be a missing underscore in your code?) and it returns to "somewhere". I think you need a Goto Loop1 or whatever right after the DEBUG satement - but I just had a quick look at it so I may be missing something.

/Henrik.

[mackrackit]

Golden rule for interrupts.
Once in get out as quick as possible.
My guess is GOSUB a time or two will violate the golden rule.

Yes, seeing the whole code could help

[HankMcSpank]

Golden rule for interrupts.
Once in get out as quick as possible.
My guess is GOSUB a time or two will violate the golden rule.

Yes, seeing the whole code could help

I no longer have Gosubs in my interrupt - I removed them.

The problem seems to be the Gosub in the main body of code - when I leave them in, the IOC interrupt routine or my program hangs once in every 8-10 switch presses.
(not sure which yet...when it hangs, the last debug line I see is that from inside in the interrupt routine!)

I'm presently trimming my bloaty program right down (most of it is just visual 'white noise' lol!)...once i've slimmed it down but can still replicate the problem I'm experiencing, then I'll post up the code....at least then you'll have a chance of picking through it!

Henrik - re the missing underscore - that was just a rough high level example of my approach - not my code (& it was *very* late UK time!)

[HenrikOlsson]

Hank,
Yes, that would be nice, please post the with which you are actually having problems... ;-)
But if it's like the code you DID post I still think though that there's a missing Goto Main or Goto Loop1 or whatever as per my previous post.

And, regarding the GOSUBs, there's really nothing preventing you from having a PAUSE 10000 in the ISR, it'll work. That "golden rule" is there to allow any software timings etc in the main loop to stay as accurate as possible. I still don't understand why using a GOSUB in the ISR would cause problem but that discussion is moot since that, for sure, is no longer the cause of the problem in this case.

/Henrik.

[Acetronics2]

Hi, Hank

as far as I can understand what you try to do ... ( ) I do not see any GIE bit cancelling before entering sleep ... nor the traditionnal "@NOP" placed right after the " @Sleep " ...

Regards

Alain