Stack Under flow

[Wayne]

Hi Steve
You only get the error if you use the MPLAB SIM tool or program the PIC
and install it in the board.


Thanks
Wayne

[mister_e]

So to be clear does

main:
GoSub getkey
Goto Start     ' <=== Add this line

getkey:
kp1=0 'Clear kp1

fix the problem... i guess yes !?!

[Wayne]

Hi Steve (MR. E)

Yes that did work and thank you very much for the help.
But one more thing WHY and what is a stack underflow?

Again Thanks

Wayne

[mister_e]

A short explanation:
once the program RETURN from GETKEY, it RETURN after the GOSUB line, then do once again the GETKEY sub, meet a RETURN without a previous gosub.

Gosub => stack+1 => stack = +
Return => stack-1 => stack = 0
Return +> stack-1 => stack=-1 <=== here's the underflow

[Wayne]

OK makes sence


Again Thanks for your help




Wayne