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LCD_RW BIT P2.6
LCD_EN BIT P2.5
LCD_DATA EQU P0 //数据并行口
ECHO BIT P3.6 //回波信号
TRIG BIT P3.7 //触发信号
LED BIT P2.0 //报警
BEE BIT P2.1
water_in BIT P2.2
water_out BIT P2.3
TIME_FULL BIT 20H
START_FLAG BIT 21H
TX EQU 40H //定时器用
S_HH EQU 41H //距离上限高8位
S_HL EQU 42H //距离上限低8位
S_H EQU 45H //距离高8位
S_L EQU 46H //距离低8位
SET_FLAG EQU 47H
ORG 0000H
LJMP MAIN
ORG 000BH //定时器0入口
LJMP TIME0
ORG 001BH
LJMP TIME1
ORG 0030H
MAIN:
CLR TRIG
CLR TIME_FULL
MOV SP,#52H //预置堆栈地址
MOV R0,#40H
MOV A,#0
CLR_ADD: //把40H-5FH的内容清零
MOV @R0,A
