n10-2-1.asm

书籍8051入门篇

;N10-2-1.ASM
;XTAL=11.0592MHz
$MOD51
RESET		EQU	0000H
ENTRY_T0	EQU	000BH
P_START		EQU	0030H
SCOPE_CH1 	EQU	P1.0
MS10		EQU	-9217		;10ms
V_H		EQU	HIGH(MS10)
V_L		EQU	LOW(MS10)
;
		ORG	RESET
		LJMP	START		; MAIN PROGRAM
		ORG	ENTRY_T0
		LJMP	T0_ISR		; TIMER0 INTERRUPT
;
		ORG	P_START
START:		SETB	SCOPE_CH1	; INITIALIZE P1.0 = 1
		MOV	TMOD,#11H	; TIMER0 = MODE1
		MOV	TH0,#V_H	; (65536-9217) / 256
		MOV	TL0,#V_L	; (65536-9217) % 256
		CLR	TF0		; CLEAR TF0 FLAG
		SETB	TR0		; START TIMER0
		SETB	ET0		; ENABLE TIMER0 INTERRUPT
		SETB	EA		; START INTERRUPT
LOOP:		SJMP	LOOP
;
T0_ISR: 	CPL	SCOPE_CH1	; CPL P1.0
		CLR	TF0		; CLEAR TF0 FLAG
		MOV	TH0,#V_H	; (65536-9217) / 256
		MOV	TL0,#V_L	; (65536-9217) % 256
		RETI			; RETURN FROM INTERRUPT
		END