9-4-2.asm

来自「书籍8051入门篇」· 汇编 代码 · 共 21 行

;9-4-2.ASM
$MOD51
	ORG	0000H
START:	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
	CPL	P1.0		; CPL P1.0
	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