Interrut Driven Oscillator

[Darrel Taylor]

Ben,

Maybe a few more comments in the ASM routine will help.

ASM
    RST?RP                         ;        Set to BANK0
    BCF     T1CON,TMR1ON           ;        Turn off timer
    MOVF    _TMR1Reload ,W         ;  1      Get LOW byte of TMR1Reload 
    ADDWF   TMR1L,F                ;  1      add it to LOW byte of TMR1
    BTFSC   STATUS,C               ;  1/2    If addition caused a carry
    INCF    TMR1H,F                ;  1      add carry to HIGH byte of TMR1
    MOVF    _TMR1Reload+1,W        ;  1      Get HIGH byte of TMR1Reload
    ADDWF   TMR1H,F                ;  1      add it to HIGH byte of TMR1
    BSF     T1CON,TMR1ON           ;  1     Turn TIMER1 back on
ENDASM

HTH,
    Darrel