changing chips, 12C508A to 12F629.....

[SnM]

will my code for a 12C508A chip be compatable with the 12F629? I want to start using a flashable chip, but still would like an 8 pin chip. When I get time i will look over the data sheet, but I didn't know if there was some big differences....

looking at microchips site, it looks like the 12F629 runs at 20MHz... anyway that chip can run at 4MHz?

thanks, steve

 

[Nigel Goodwin]

will my code for a 12C508A chip be compatable with the 12F629? I want to start using a flashable chip, but still would like an 8 pin chip. When I get time i will look over the data sheet, but I didn't know if there was some big differences....

The 12C508 is a 12 bit core, the 12F629 is a 14 bit core - this means the 12F has all the instructions of a 12C, plus a couple more - so the code will work fine. There are a few slight changes you need to make to the code though, basically setting the oscillator and other hardware settings - you need to study the datasheets for both chips, but the actual program code itself will transfer over directly.

looking at microchips site, it looks like the 12F629 runs at 20MHz... anyway that chip can run at 4MHz?

thanks, steve

That's it's maximum working frequency, it has an internal oscillator which can be set to 4MHz, just like the 12C508 - again, consult the datasheet.

 

[SnM]

thanks for the help. figuring out the differences in hardware setup shouldn't be a problem

thanks again!!!

steve

 

[Matt(Pic progger)]

:idea:

Use this code to calibrate the osc on this chip.......

CALL H'03FF' ;GET OSC CALLIBRATION

BSF STATUS,RP0 ;SWITCH TO BANK1

MOVWF OSCCAL ;SETUP OSC CAILIBRATION

BCF STATUS,RP0 ;SWITCH TO BANK0

This is different from the 50x, don't get caught out like I did!

Hope this helps!