9-6-1.asm

书籍8051入门篇

;9-6-1.ASM
$MOD51
	ORG	0000H
START:	MOV	R0,#100		; TIMER BUFFER		 (1)
	MOV	TMOD,#11H	; SET TIMER0 TO MODE1
	MOV	TH0,#0D8H	; (65536-10000) / 256
	MOV	TL0,#0F0H	; (65536-10000) % 256
	SETB	TR0		; START TIMER0
;
LOOP:	JNB	TF0,LOOP	; WAIT FOR OVERFLOW
	ACALL	T0_RELOAD	; RELOAD TIMER0 SETTINGS
	DJNZ	R0,LOOP		; 100 COUNTS FOR 10ms	 (2)
	MOV	R0,#100		; RELOAD 100 COUNTS	 (3)
	CPL	P1.0		; CPL P1.0 FOR 1s
	SJMP	LOOP		; WAIT FOR OVERFLOW AGAIN
;
T0_RELOAD:
	CLR	TR0		; STOP TIMER0
	MOV	TH0,#0D8H	; (65536-10000) / 256
	MOV	TL0,#0F0H	; (65536-10000) % 256
	CLR	TF0		; CLEAR TIMER0 OVERFLOW FLAG
	SETB	TR0		; START TIMER0
	RET
;
	END