n9-1-1.asm

书籍8051入门篇

;N9-1-1.ASM
MS10	EQU	10000
V_HBYTE	EQU	(-MS10)/256
V_LBYTE	EQU	(-MS10) MOD 256
;
$MOD51
	ORG	0000H
START:	MOV	TMOD,#01H		; SET TIMER0 TO MODE1
	ACALL	T0_RELOAD		;CALL RELOAD FUNCTION
;
LOOP:	JNB	TF0,LOOP		; WAIT FOR OVERFLOW
	ACALL	T0_RELOAD		; RELOAD TIMER0 SETTINGS
	CPL	P1.0			; CPL P1.0
	AJMP	LOOP			; WAIT FOR OVERFLOW AGAIN
;
;SET TIMER0 FOR 10mS (XTAL=12MHz)
T0_RELOAD:
	CLR	TR0			; STOP TIMER0
	MOV	TH0,#V_HBYTE
	MOV	TL0,#V_LBYTE
	CLR	TF0			; CLEAR TIMER0 OVERFLOW
	SETB	TR0			; START TIMER0
	RET
	END