16F876 : settings for 40Mhz

[mister_e]

It really looks like your programmer don't set the configuration fuses...

i don't have any 18F252, but this one is tested with a 18F452

@ __CONFIG _CONFIG1H, _OSCS_OFF_1H & _HSPLL_OSC_1H
    ' Oscillator switch OFF
    ' Use HSPLL (fosc X 4) oscillator  (10mhz here)
    '
@ __CONFIG _CONFIG2L, _BOR_ON_2L & _PWRT_ON_2L & _BORV_45_2L
    ' Brown out reset ON @ 4.5Volts
    ' Power-up timer ON
    '
@ __CONFIG _CONFIG2H, _WDT_ON_2H 
    ' Watch dog timer ON
    '
@ __CONFIG _CONFIG4L, _STVR_ON_4L & _LVP_OFF_4L & _DEBUG_OFF_4L
    ' Stack over/underflow ON
    ' Low Voltage programming OFF
    ' Background debugger OFF
    
Define OSC 40
Start:
      Toggle PORTC.3
      pauseus 100
      goto start

if you change the DEFINE OSC 40 to DEFINE OSC 10 you'll get 25uSec pulses. So PLL is working very well.

Look into your Melabs programmer setings, must have a place to configure programmer options.

If you can't find something like that, send an e-mail to BRUCE from Reynolds Electronics. [email protected] For sure he know the solution for that.

[mischl]

steve, thanks a lot for the example. this is working very well!

after that my own example works too. unfortunalety i don't know why... i think it was a configuration at the melabs programmer.

once again : thanks all for the support

[mister_e]

mischl

great to know it's working now.

Have fun!

[Bruce]

With the melabs serial programmer make sure you have these two
menu options selected.

Update Configuration From File
Reread File Before Programming

This makes sure you are always getting the latest version of the .hex
file & whatever config word changes you make programmed into the
target.

Also, I recommend inserting "every" config word option the target has.
This way there is no doubt how each option is configured.

With all of the advanced configuration options the 18F series has, It's in
your best interest to know exactly how every option is set. Accepting a
default un-programmed state may cause you problems.

For the 18F series I comment out every default setting in the PBP device
header file, and insert my own config fuse settings in my source.