How do I figure out what went wrong

imekon

I've put together a Propeller chip and memory onto a custom board, fired it up. I plugged in a prop clip - it indicates there is a propeller chip present - it lets me download to ram or to rom - does that mean that everything should be working?

I have an LED attached to pin 5 (P4) so I tried setting it to turn it on, however I see no signal on the output - so I tried different outputs and nothing seemed to work.

I can see a 10MHz signal on the crystal.

Not sure where to go from here.

Harprit

We need to look at your code.
Harprit

imekon

{{
  Toggle various pins
}}

CON
  _clkmode = xtal1 + pll16x
  _xinfreq = 10_000_000

  pin = 4

var
  long t
  
PUB toggle
  dira[noparse][[/noparse]pin]~~

  outa[noparse][[/noparse]pin] := 0

  t := cnt
  
  repeat
    t += clkfreq / 111
    !outa[noparse][[/noparse]pin]
    waitcnt(t)
    t += clkfreq / 21
    !outa[noparse][[/noparse]pin]
    waitcnt(t)
    t += clkfreq / 15
    !outa[noparse][[/noparse]pin]
    waitcnt(t)
     

Mike Green

For a start, you can't run the Propeller at 160MHz (10MHz x 16). Try using PLL8X instead of PLL16X.

Harprit

try this

CON
_CLKMODE=XTAL1+ PLL2X 'The system clock spec
_XINFREQ = 5_000_000 'crystal frequency

Con
pin=5

PUB Demo 'subroutine to toggle the output line

dira[noparse][[/noparse]pin]~~ 'gain access to line
repeat
!outa[noparse][[/noparse]pin]
waitcnt(clkfreq/4+cnt)

imekon

Mike Green said...
For a start, you can't run the Propeller at 160MHz (10MHz x 16). Try using PLL8X instead of PLL16X.

Thank you! Now the LED is flashing quite happily!

Phew, thought I'd created a duff board

imekon

Here are some photos of the partly populated board I'm working on:

http://imekon.blogspot.com/search/label/Hardware