picbasic +12c508a+soft_stack error

[Bruce]

It might work on one series, but I wouldn't count on it as being reliable across the board.
I have seen various PICs come up with totally random values in port latches at POR, so
you really do need to clear portb latches first if it's to be reliable.

[mister_e]

i'm thinking of something using interrupt.. not sure if it could reduce things to 8-10 words... mmm..

[Bruce]

I had considered that approach too, but more than half of your code space (or more) would
be eaten up with interrupt configuration setup.

Making it "reliable" with less than 13 words is going to be a real task.

[mister_e]

yup, but where is it stated that it has to be reliable, where it is stated that we need to use the same PIC and hardware ?

i still believe it's doable... but with some hair lost

[Darrel Taylor]

yup, but where is it stated that it has to be reliable?

I think that's a given. It has to work when you turn on the power.
As for the rest of the rules, well, I'm assuming No EEPROM is the only one. Edit: with a 16F628A

i still believe it's doable... but with some hair lost

I'm starting to believe NO.
But I haven't given up yet.

I've got 3 completely different versions at 13 words now.
1 using external circuitry to TMR0
1 using external circuitry to a comparator
and another that simply shaves a word off my 14 word program. (wish I'd done that to begin with)

It seems that no matter what you do to save a word, you end up having to add something to make it work.

I'm sure getting some "Quality Time" in with the datasheets though. All kinds of stuff I didn't know before.
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[mister_e]

yup all good points.. the only thing i've never dare to mess with is the stack overflow behaviour and ORG... 8 bit stack seems nice... but not sure how bad/good it behave...mmm

interesting how a led chaser can be a food for thought

[skimask]

yup all good points.. the only thing i've never dare to mess with is the stack overflow behaviour and ORG... 8 bit stack seems nice... but not sure how bad/good it behave...mmm
interesting how a led chaser can be a food for thought

Something tells me that somebody is about to break the law...
The law of diminishing returns!

Does this 'thing' have to have 8 LEDs? Or can it have 16 LEDs?
I'm thinking something along the lines of 2 LEDs per pin, back-to-back, with the common for all running to another pin...don't know what I'm thinking yet...

[skimask]

It might work on one series, but I wouldn't count on it as being reliable across the board.
I have seen various PICs come up with totally random values in port latches at POR, so
you really do need to clear portb latches first if it's to be reliable.

I don't doubt that at all...
I just checked the CARRY bit, datasheet says unknown on POR, mine come's up cleared every time (at least every time I've check anyways). That shoots that idea down...