Presetting Configuration Fuses (PIC Defines) into your Program

[mister_e]

O.K. This is ask really often. Worth to be discussed NOW!

What to do if i get "overwriting previous address content" error message?

This error is return by PBP because your configuration fuse overwrite 'PBP default'. If you open with notepad, in PBP directory, the .INC file of your PIC, let's say 16F628, the file will look like this

;**************************************************************
;*  16F628.INC                                                  *
;*                                                              *
;*  By        : Leonard Zerman, Jeff Schmoyer                   *
;*  Notice    : Copyright (c) 2002 microEngineering Labs, Inc.  *
;*              All Rights Reserved                             *
;*  Date      : 09/27/02                                        *
;*  Version   : 2.43                                            *
;*  Notes     :                                                 *
;**************************************************************
        NOLIST
    ifdef PM_USED
        LIST
        include 'M16F62x.INC'   ; PM header
        device  pic16F628, xt_osc, wdt_on, pwrt_on, mclr_on, lvp_off, protect_off
        XALL
        NOLIST
    else
        LIST
        LIST p = 16F628, r = dec, w = -302
        INCLUDE "P16F628.INC"   ; MPASM  Header
        __config _XT_OSC & _WDT_ON & _PWRTE_ON & _MCLRE_ON & _LVP_OFF & _CP_OFF
        NOLIST
    endif
        LIST

So if you try to define HS oscillator, wich is already define, you'll overwrite the previous content of the PBP setting.

To fix it, just comment those lines :

;device  pic16F628, xt_osc, wdt_on, pwrt_on, mclr_on, lvp_off, protect_off

OR

;__config _XT_OSC & _WDT_ON & _PWRTE_ON & _MCLRE_ON & _LVP_OFF & _CP_OFF

depending what you are using to compile your code, MPASM or PM.

OR some will prefer to edit those line directly... as you wish...

Where can i find the configuration fuse for my PIC ?

All the configuration fuse are in the according .INC file located in the MPLAB directory. In MPLAB 7.01, the default directory, i suppose, is C:\Program Files\Microchip\MPASM Suite.

If you open the appropriate .INC file, you will find all the configuration fuse for your PIC at the end of the file.

looks like this for a 16F628...only the end

;==========================================================================
;
;       Configuration Bits
;
;==========================================================================

_BODEN_ON                    EQU     H'3FFF'
_BODEN_OFF                   EQU     H'3FBF'
_CP_ALL                      EQU     H'03FF'
_CP_75                       EQU     H'17FF'
_CP_50                       EQU     H'2BFF'
_CP_OFF                      EQU     H'3FFF'
_DATA_CP_ON                  EQU     H'3EFF'
_DATA_CP_OFF                 EQU     H'3FFF'
_PWRTE_OFF                   EQU     H'3FFF'
_PWRTE_ON                    EQU     H'3FF7'
_WDT_ON                      EQU     H'3FFF'
_WDT_OFF                     EQU     H'3FFB'
_LVP_ON                      EQU     H'3FFF'
_LVP_OFF                     EQU     H'3F7F'
_MCLRE_ON                    EQU     H'3FFF'
_MCLRE_OFF                   EQU     H'3FDF'
_ER_OSC_CLKOUT               EQU     H'3FFF'
_ER_OSC_NOCLKOUT             EQU     H'3FFE'
_INTRC_OSC_CLKOUT            EQU     H'3FFD'
_INTRC_OSC_NOCLKOUT          EQU     H'3FFC'
_EXTCLK_OSC                  EQU     H'3FEF'
_LP_OSC                      EQU     H'3FEC'
_XT_OSC                      EQU     H'3FED'
_HS_OSC                      EQU     H'3FEE'

        LIST