m5-1.asm

来自「该源码与书本配套」· 汇编 代码 · 共 24 行

LO_TIME	EQU FFH
HI_TIME EQU 256-LO_TIME

	ORG 0H
	AJMP START
	ORG 1BH
	AJMP TIME1

	ORG 30H
START	SETB P1.0
	MOV TMOD,#00000000B
	MOV TH1,#LO_TIME
	SETB EA
	SETB ET1
	SETB TR1
	SJMP $

TIME1	JBC P1.0,LO_OUT
HI_OUT	SETB P1.0
	MOV TH1,#LO_TIME
	RETI
LO_OUT	MOV TH1,#HI_TIME
	RETI
	END