; EE 2004 ; Instructor: Bernard Chiu ; This program demonstrates two ways for implementing a lookup table. ;------------------------------------------------------------------------------ LIST P=18F4520 ;directive to define processor #include ;processor specific variable definitions ;------------------------------------------------------------------------------ ORG 0x000000 bra Main ORG 0x000008 ; Check which interrupt flag is raised, branch to the ; appropriate ISR. ORG 0X000018 bra T0_ISR Main: clrf TRISD clrf PORTD movlw 0x02 ; Prescale 1:8 movwf T0CON movlw 0x0B movwf TMR0H movlw 0xDC movwf TMR0L bsf RCON, IPEN bsf INTCON, TMR0IF bsf INTCON, TMR0IE bsf INTCON2, TMR0IP bsf INTCON, GIEH bsf INTCON, GIEL Over: bsf T0CON, TMR0ON btfsc PORTC, 2 bra T0_ISR btfss INTCON, TMR0IF bra Over bra$ T0_ISR: btfss INTCON, TMR0IF retfie bcf INTCON, TMR0IF incf PORTD retfie INT0_ISR: bcf INTCON, TMR0IF bsf T0CON, TMR0ON bsf TRISB, 6 ; Set it to RB6 btg PORTD, RD0 ; Toggle led on retfie INT1_ISR: bcf INTCON, TMR0IF bsf T0CON, TMR0ON bsf TRISB, 7 btg PORTD, RD0 retfie end