實(shí)驗(yàn)二 COMPARE 與PWM.doc

實(shí)驗(yàn)二 COMPARE 與PWM一、試驗(yàn)?zāi)康模?、 學(xué)習(xí)CCP功能模塊的原理與應(yīng)用2、 進(jìn)一步學(xué)習(xí)中斷的概念及其編程3、 應(yīng)用CCP模塊解決實(shí)際問題二、試驗(yàn)參考程序 INCLUDEP16f877a.inc ORG 0x00 ;GOTO START ORG 0x04 BCF STATUS,RP0 BTFSC PIR2,CCP2IF ; Test CCP2 Interrupt GOTO CCP_ISR ; Goto CCP Interrup Service RoutineRETFIESTART: CALL PIC_INITMAIN_LOOP: NOP GOTO MAIN_LOOPPIC_INIT: CLRF INTCON BSF STATUS, RP0 ; Choose BanklMOVLW B11111001 ; MOVWF TRISC ; Port C direction CLRF PIE2 BSF PIE2,CCP2IE ; Enable CCP2 InterruptBSF PIE1,CCP1IE ; Enable CCP2 Interrupt BCF STATUS, RP0 CLRF PORTC MOVLW B00110001 MOVWF T1CON ; MOVLW B00001000 ;比較方式，匹配時輸出為1,雙色LED紅燈亮 MOVWF CCP2CON ; Compare Mode, Outpuu 1 as InterruptMOVLW B00001001 ;比較方式，匹配時輸出為0雙色LED綠燈滅 MOVWF CCP1CON ; Compare Mode, Outpuu 0 as Interrupt MOVLW 0xF4 MOVWF CCPR2H MOVWF CCPR1H MOVLW 0x24 ; CCPR2H:CCPR2L=0xF424=62,500MOVWF CCPR2L ; 62,500x8us=0.5sMOVWF CCPR1L ; 62,500x8us=0.5s BSF INTCON,PEIE ; Enable Peripheral Interrupn BSF INTCON,GIE ; Enable Global Interrupn RETURN CCP_ISR: BCF PIR2,CCP2IF ; Clear CCP2 Interruput Flag MOVLW B00000001 ; Toggle Bit0 of CCP2CON XORWF CCP2CON,F ; 1001=比較方式，匹配時輸出為0 BCF PIR1,CCP1IF ; Clear CCP2 Interruput Flag MOVLW B00000001 ; Toggle Bit0 of CCP1CON XORWF CCP1CON,F ; 1000=比較方式，匹