## 4.7.17 Configuration Bits

Configuration bits (also known as fuses) can be configured using one of two methods:

- using #pragma config (see section 4.7.6), which is a preferred method for the new code. Example:

  #pragma config CP0=OFF,OSCS=ON,OSC=LP,BOR=ON,BORV=25,WDT=ON,WDTPS=128,CCP2MUX=ON

  #pragma config STVR=ON

- using `__code' and `__at' modifiers. This method is deprecated. Possible options should be ANDed and can be found in your processor header file. Example for PIC18F2550:

  #include <pic18fregs.h> //Contains config addresses and options
  static __code char __at(__CONFIG1L) configword1l =
  _USBPLL_CLOCK_SRC_FROM_96MHZ_PLL_2_1L &

  _PLLDIV_NO_DIVIDE__4MHZ_INPUT__1L & [...];
  static __code char __at(__CONFIG1H) configword1h = [...];
  static __code char __at(__CONFIG2L) configword2l = [...];
  //More configuration words

Mixing both methods is not allowed and throws an error message ”mixing __CONFIG and CONFIG directives”.