ch14_b11-3.asm

51单片机基础篇 对于有一定基础的人看看 包含书中所以的源代码

     ;PROGRAM  NAME B11-3.ASM
     MS10    	EQU  	9217   		        ;APPROXIMATELY 10ms INTERRUPR
     INTR_CNT   EQU  	30H   		        ;CNT STORIAGE
     BUFFER 	EQU  	31H   		        ;DISPLAY BUFFER
     ;
     SCOPE 	REG  	P3.3  		        ;CHECK BY SCOPE
     BUZZER	REG  	P3.4
     LED    	REG  	P3.7
     ;
           	ORG  	0000H
           	JMP  	START
           	ORG  	0003H  		        ;[DISABLE]  EXTERNAL INT0 INTERRUPT
           	RETI
           	ORG  	000BH   		;[ENABLE]  TIMER0 OVERFLOW INTERRUPT
           	JMP  	T0_ISR
     ;
           	ORG  	0013H
           	RETI            		;[DISABLE] EXTERNAL INT1 INTERRUPT
             	ORG   	001BH
             	RETI            		;[DISABLE] TIMER1 OVERFLOW INTERRUPT
             	ORG   	0023H
             	RETI            		;[DISABLE] SERIAL INTERRUPT
     ;
             	ORG    	30H
     START  	MOV   	R0,#00H
            	DJNZ  	R0,$   		        ;DELAY A WHILE
            	MOV   	SP,#60H
            	MOV    	P1,#FFH
            	MOV   	P3,#FFH
            	MOV   	INTR_CNT,#00H
            	CLR   	BUZZER 		        ;P3.4=0,BUZZER OFF
            	CLR   	LED    		        ;P3.7=0,LED OFF
            	MOV   	BUFFER,#12H	        ;DISPLAY DATA
     ;
            	CALL  	SET_TMR0
     $LOOP 	SJMP  	$LOOP
     ;
     T0_ISR	SETB  	SCOPE
            	MOV   	TH0,#(65536-MS10)/256   ;RELOAD TH0
            	MOV   	TL0,#(65536-MS10).MOD. 256
             	PUSH  	A
     ;
          	MOV   	A,BUFFER
            	ANL   	A,#0FH  		;GET LOW NIBBLE
            	SETB  	ACC.5   		;BIT5=1
            	MOV   	P1,A    		;SHOW 1 DIGIT
            	MOV   	R0,#30H
            	DJNZ  	R0,$   		        ;DELAY
     ;inter-blanking
            	CLR    	ACC.4
            	CLR    	ACC.5
            	MOV   	P1,A   		        ;ALL DIGIT BLANK
            	MOV   	R0,#04H
            	DJNZ  	R0,$  		        ;DELAY
     ;
            	MOV   	A,BUFFER
             	ANL   	A,#F0H 		        ;GET HIGH NIBBLE
            	SWAP  	A       		;SWAP A
            	SETB  	ACC.4   		;BIT4=1
            	MOV   	P1,A    		;SHOW ANOTHER DIGIT
            	MOV   	R0,#30H
            	DJNZ  	R0,$   		        ;DELAY
     ;
            	CLR   	ACC.4
            	CLR   	ACC.5
            	MOV   	P1,A   		        ;ALL DIGIT BLANK
     ;
     ;INTR_CNT+1
             	INC    	INTR_CNT
             	MOV    	A,INTR_CNT
             	CJNE   	A,#100,$T0_END
             	MOV    	INTR_CNT,#00H
     $T0_END	POP    	A
             	CLR    	SCOPE
             	RETI
     ;
     SET_TMR0
            	MOV   	A,#01H  		;TIMER MODE 1
            	MOV   	TMOD,A
            	MOV   	TH0,#(65536-MS10)/256   ;RELOAD TH0
            	MOV   	TL0,#(65536-MS10).MOD. 256
            	CLR   	TF0     		;CLEAR TIMER0 FLAG
            	SETB  	TR0     		;TIMER0 START COUNT
            	SETB  	ET0     		;ENABLE TIMER0 INTERRUPT
            	SETB  	EA      		;ENABLE SYSTEM INTERRUPT
            	RET
     ;