Why the difference between these two button reading programs in PASM and SPIN

Tony B.

I am working on a Propeller Professional Development Board using button Zero and LED 9. Both programs work as coded, but with this one puzzling result. When I run the PASM code and while it is waiting for the a button press the LED is dimly lit. When you press and hold the button the LED is brightly lit as you would expect. Release the button and the LED returns to the dimly lit state. The SPIN code works as well, but the LED is off until the button is pressed and held. I'm returning to working with PASM because I am beginning a project which needs it. I was reviewing some learning/practice code I had worked with for some time and rediscovered this old problem I never got figured out.

CON
  _clkmode = xtal1 + pll16x      ' Enable External Crystal and PLL X 16
  _xinfreq = 5_000_000           ' External Crystal Frequency 5Mhz
PUB Main
  {Launch cog to run Propeller Assembly code}
  cognew(@entry, 0) 'Launch new cog

DAT
        org       0                             'Begin at Cog RAM address 0
              
entry   mov       dira, LED                     'Set pin 9 to output
loop    waitpeq   Button, Button                'Wait till button is pressed
        xor       outa, LED                     'Turn on LED
        waitpne   Button, Nobutton              'Wait till button is released
        xor       outa, LED                     'Turn off LED
        jmp       #loop                         'Loop
        
 
LED       long    |< 9
Button    long    0
Nobutton  long    |< 0    

CON
  _clkmode = xtal1 + pll16x       ' Enabled External Crystal and PLL X16
  _xinfreq = 5_000_000            ' External Crystal Frequency
VAR
  
OBJ
     
PUB Main
    dira[9] := 1
  repeat     
    waitpeq(%0, %1, 0)
     
    outa[9] := 1
     
    waitpne(%0, %1, 0)
     
    outa[9] := 0

Thanks,
Tony

kuroneko

Your PASM waitpeq uses 0 as a mask and target which makes it effectively a 6 cycle nop. If you want to wait use non-zero masks, e.g.

waitpeq mask, mask    ' wait for pin high
        waitpne mask, mask    ' wait for pin low

mask    long    |< pin

Tony B.

Thanks Kuroneko. Problem solved.