__CONFIG _CONFIG1, _LVP_OFF & _FCMEN_ON & _IESO_OFF & _BOR_OFF & _CPD_OFF & _CP_OFF & _MCLRE_ON & _PWRTE_ON & _WDT_OFF & _INTRC_OSC_NOCLKOUT
__CONFIG _CONFIG2, _WRT_OFF & _BOR21V
Later after at the begining of the program
BANKSEL OSCCON ;bank2
MOVLW b'01100001' ;low frequency internal oscillator 1mhz
MOVWF OSCCON
BCF OPTION_REG, T0CS ;1=use tock pin (ie off), 0=use internatl timer ir on.
BCF OPTION_REG, 3 ;Assign prescalar to Timer0 = 0, to WDT = 1
BCF OPTION_REG, 2 ;set scalar 000 = 1:2 011 = 1:16 110 = 1:128
BCF OPTION_REG, 1 ; 001 = 1:4 100 = 1:32 111 = 1:256
BCF OPTION_REG, 0 ; 010 = 1:8 101 = 1:64 ;
BSF INTCON, T0IE ;enable Timer 0 interupts
BSF INTCON, GIE ;enable interupts globaly