Programming 12f629 - some tips

[roman]

I have been programming this device for a few days now and can offer these observations which may help.

The 12F629 does not have an A/D converter but you still need to set the Analog Select (ANSEL)register and the Comparator Control (CMCON) register to get the digital i/o working. i.e.

#byte CMCON=0x19
#byte ANSEL=0x9f

main() {

CMCON=0x07; // Comparator off.
ANSEL=0x00; // All i/o digital.

// Normal i/o commands i.e. output_low will now work

}


The #fuses INTRC and INTRC_IO compile to produce a call to 3FFh in order to load the clock calibration value. If the pre-loaded RETLW XX instruction has been erased by erasing the whole device (very easy to do with the PromateII, but not as easy to recover ) then the program will hang. This would explain some of the problems reported.

The PICkit 1 Flash starter kit works well with MPLAB and has the very useful facility of being able to re-calculate and re-load the calibration value at 3ffh.

Hope this helps, and I hope this post does not disappear into the ether as my last one did

[burnsy]

Thanks, that worked well for me too.
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This is the last code change until its ready....