文档介绍：;程序名:密码锁
;功能描述:四位密码保存在EEPROM中,开机输入密码错误,等待重新输入
;密码输入正确,密码锁打开;此状态下,可以修改新密码
ENTER_FLAG BIT 03H
ORG 0000H
SJMP MAIN
ORG 000BH
;LJMP IPT0
ORG 001BH
LJMP IPT1
ORG 0030H
MAIN: CLR ENTER_FLAG
MOV TMOD,#10H
MOV TH1,#HIGH(65536-50000)
MOV TL1,#LOW(65536-50000)
SETB ET1
SETB EA
MOV 70H,#10
MOV 50H,#10
MOV 51H,#10
MOV 52H,#10
MOV 53H,#10
LCALL DISP
MOV R3,#4
MOV R2,#0
MOV R0,#30H
M_LOOP1:MOV 3DH,R2
LCALL EEP_RD
;LCALL D20MS
MOV ***@R0,A
INC R0
INC R2
DJNZ R3,M_LOOP1
M_LOOP: MOV R1,#40H
MOV R4,#4
M_LOOP2:LCALL M_KEY
JNB F0,M_LOOP2
CLR F0
MOV ***@R1,A
INC R1
DJNZ R4,M_LOOP2
MOV R0,#30H
MOV R1,#40H
MOV R5,#4
M_LOOP3:MOV A,***@R0
CLR C
SUBB A,***@R1
JNZ PW_WRONG
INC R0
INC R1
DJNZ R5,M_LOOP3
PW_RIGHT:
MOV 50H,#0
MOV 51H,#0
MOV 52H,#0
MOV 53H,#0
LCALL DISP
MOV 70H,#20
CLR
SETB TR1
M_LOOP4:LCALL M_KEY
JNB F0,M_LOOP4
CLR F0
CJNE A,#0BH,M_NEXT1 ;非回车键跳转
CPL ENTER_FLAG
JB ENTER_FLAG,M_NEXT2
MOV R5,#0
MOV R4,#4
MOV R0,#50H
M_LOOP5:MOV 3EH,R5
MOV A,***@R0
MOV 3FH,A
LCALL EEP_WR
LCALL D20MS
INC R5
INC R0
DJNZ R4,M_LOOP5
MOV 50H,#10
MOV 51H,#10
MOV 52H,#10
MOV 53H,#10
LCALL DISP
SJMP $
M_NEXT2:MOV 70H,#40
CLR
SETB TR1
SJMP M_LOOP4
M_NEXT1:JNB ENTER_FLAG,M_NEXT3
CPL ENTER_FLAG
SJMP M_LOOP4
M_NEXT3:
MOV 50H,51H
MOV 51H,52H
MOV 52H,53H
MOV