Newson Edouard <PICLIST@MITVMA.MIT.EDU> wrote:

> I am using the PIC16C74 and wonders if it is possible to program the
> configuration fuses such as watchdog, crystal selections, code
> protection, et straight from assembly instead of programming them
> manually at the programmer terminal.

Newson:

The following is an excerpt from my web page... It's Question #35 in the
PIC16/17 section of the Embedded Systems Programming Answer Line.

------------------------------------------------

I'm using MPASM for the 16C74. Is it possible to set configuration fuses in my
source code?

     Sure, as long as you're using a version of MPASM later than about 1.20.
     Here's an example for the 16C74. In your own code, you should probably use
     the fuse-definition equates that are included in the "16CXX.INC" and
     "17CXX.INC" files distributed with MPASM, since they're guaranteed to have
     the correct values for current parts.

         ; NOTE:  THIS IS FOR THE CURRENT VERSION OF THE 16C74 ONLY!

         CP_ALL  EQU     03F8FH          ;NOTE:  These equates are for the
         CP_75   EQU     03F9FH          ;       current version of the
         CP_50   EQU     03FAFH          ;       PIC16C74 ONLY!
         CP_OFF  EQU     03FBFH          ;
         PWRT    EQU     03FBFH          ;       They are NOT for the 16C74A,
         NO_PWRT EQU     03FB7H          ;       nor are they guaranteed to
         WDT     EQU     03FBFH          ;       work on any other devices.
         NO_WDT  EQU     03FBBH          ;
         LP_OSC  EQU     03FBCH          ;
         XT_OSC  EQU     03FBDH          ;
         HS_OSC  EQU     03FBEH          ;
         RC_OSC  EQU     03FBFH          ;

                 __FUSES CP_ALL & PWRT & NO_WDT & XT_OSC   ;Enable code
                                                           ;protection and
                                                           ;power-up
                                                           ;timer, disable
                                                           ;the watchdog
                                                           ;timer, and
                                                           ;select XT
                                                           ;oscillator.

     Note that the __FUSES directive is preceded by two underscores, not one.

-----------------------------------------------------------

-Andy

Andrew Warren - fastfwd@ix.netcom.com
Fast Forward Engineering, Vista, California
http://www.geopages.com/SiliconValley/2499