I have trouble with the pin stimulus file in MPSIM. I want to change the
PORTB status
at a certain time in my program. I have something like this:

        MOVF  PORTB,0           ; place portB-status in W
        XORLW k0                     ; button 0?
        BTFSC STATUS,Z
        GOTO  KNAPP0             ; Yes, CALL SUBRUTINE
        ...No, continue...

How do I make the stimulus to happen just before the MOVF PORTB,0
instruction
executes? I know it has something to do with the STEP number in the
stimulus file. What
is step? Is it number of steps (with for example F7 in MPLAB) until the
PC reaches the specific code?

Another question when I'm writing:
I write a program that scans a 0-9 keyboard. When 0 is pressed the
PORTA:0 gets low and when you press the 1 the PORTA:0 goes high. The
strange phenomen is that if you press the 1 the PORTA:0 goes high, but
just for ca 2 seconds and then it goes back low to be low. I have tried
to take away the code for the 0 button, thats clear the PORTA:0 bit but
newertheless the PORTA:0 goes low. I can't find anything in the code
that sets the PORTA:0 low after this change but still it goes low.
Every interrupt is cleared, I think.

/Niclas Olsson <e94no@efd.lth.se>