Code_20.asm

;*******************************************************
;*  Description  :  Using Timer0 and Timer1 
;*   
;*******************************************************
    
    #INCLUDE<P18F452.INC>
    CONFIG WDT=OFF
    CONFIG OSC=HS
    CONFIG OSCS=OFF
    
    ORG 0H
    GOTO MAIN
    
    ORG 0008H
    BTFSS INTCON,TMR0IF
    RETFIE
    GOTO T0_ISR

    ORG 100H 
MAIN BSF TRISC,6
    BCF TRISD,1
    BCF TRISB,7
    MOVLW 0x08
    MOVWF T0CON
    MOVLW 0x63
    MOVWF TMR0H
    MOVLW 0xBF
    MOVWF TMR0L
    BCF INTCON,TMR0IF
    BSF T0CON,TMR0ON
    BSF INTCON,TMR0IE
    BSF INTCON,GIE

OVR BTFSC PORTC,6   ;POLLING RC6
    GOTO ATW
    BRA OVR
    
    ORG 200H
ATW BCF INTCON,TMR0ON  ;1KHz @ RB7 AND RD1 HIGH
    BCF TRISB,7
    BCF TRISD,1
    BSF PORTD,1        
    MOVLW 0x30
    MOVWF T1CON
    
HERE MOVLW 0xF6  
    MOVWF TMR1H
    MOVLW 0x3B
    MOVWF TMR1L
    BCF PIR1,TMR1IF
    CALL DELAY
    BTG PORTB,7
    BRA HERE
    RETURN
    
DELAY BSF T1CON,TMR1ON
AGAIN BTFSS PIR1,TMR1IF
    BRA AGAIN
    BCF PIR1,TMR1ON
    RETURN

    ORG 500H
T0_ISR MOVLW 0x63  ;500HZ @ RD1
    MOVWF TMR0H
    MOVLW 0xBF
    MOVWF TMR0L
    BTG PORTD,1
    BCF INTCON,TMR0IF
    RETFIE
    END