;***************************************************
;*???? 用單片機89C2051制作的延時控制器????? *
;*????? T0、TT0配合構成為秒脈沖發生器????????????? *
;*????? TSBIN 為秒計數器（二進制，0~60) ；21H單元? *
;*????? TMBIN 為分計數器（二進制，0~60) ；22H單元? *
;*????? THBIN 為時計數器（二進制，0~24) ；23H單元? *
;*????? KEYCODE 為鍵盤值；29H單元????????????????? *
;*????? KEYPRE 為按鍵標志字；PSW.5???????????????? *
;*????? 當倒計時至00H00M00S 時，P3.0, P3.1端輸出?? *
;*????? 反相信號。???????????????????????????????? *
;*????? S1----對時按鈕；S2－－對分按鈕；?????????? *
;*????? S3－－對秒按鈕；S4－－退出對時???????????? *??
;***************************************************

?TMSBIN EQU 20H
?TSBIN EQU 21H
?TMBIN EQU 22H
?THBIN EQU 23H
?KEYCODE EQU 29H
?TT0 EQU 2BH
?OUT EQU 2DH

?KEYPRE BIT PSW.5
?
?DPS1 DATA 11001111B?;S4
?DPM0 DATA 11010111B?;S3
?DPM1 DATA 11011111B?;S2
?DPH0 DATA 11100111B?;S1
?DPH1 DATA 11101111B
?HIDE DATA 11111111B?;消隱字

?ORG 0000H
?AJMP MAIN

?ORG 000BH
?SJMP I_T0

?ORG 001BH
I_T1:?AJMP MAIN1
?RETI

;***********?? T0中斷服務??? ***********
?ORG 0030H
I_T0:?PUSH ACC
?PUSH PSW
?MOV TH0,#0DCH??;0.01s時間，常數因子為DC00H
?;MOV TL0,#00H?
?CLR C
?MOV A,TMSBIN
?SUBB A,#01H
?MOV TMSBIN,A
?MOV R3,TT0??
?DJNZ R3,I_T01??;中斷次數<100（每次中斷0.01S）,轉出
?CPL KEYPRE
?MOV R3,#100??;中斷次數＝100次，重新下一個計數
?MOV TMSBIN,#100
?CLR C
?MOV A,TSBIN??;秒計數器加1
?SUBB A,#01H
?MOV TSBIN,A
?;SUBB A,#60 ??;秒計數器>59?? Y，秒計數器＝00
?JNC I_T01
?MOV A,TMBIN
?ADD A,THBIN
?JNZ M1
?MOV OUT,#11111101B
?CLR TR0
?MOV TSBIN,#00H
?SJMP I_T01
M1:?MOV TSBIN,#59
?CLR C
?MOV A,TMBIN??;分計數器加1
?SUBB A,#01H
?MOV TMBIN,A
?JNC I_T01
?MOV A,THBIN
?JZ I_T01
?MOV TMBIN,#59
?CLR C
?MOV A,THBIN??;時計數器加1
?SUBB A,#01H
?MOV THBIN,A
?;SUBB A,#24??;時計數器>23? Y，時計數器＝00
?JNC I_T01
?MOV THBIN,#00H
I_T01:?MOV TT0,R3
?POP PSW
?POP ACC
?RETI

?ORG 00F0H
MAIN:?MOV P1,#0FFH
?MOV OUT,#11111110B??? ;P3.0輸出低電平
?MOV P3,OUT
?MOV SP,#40H??;初始化堆棧指針??
?MOV TMOD,#11H??;T0、T1工作于16為定時器
?MOV TT0,#100
?MOV TH0,#0DCH??;T0初值
?MOV TL0,#00H
?MOV TH1,#00H??;T1初值
?MOV TL1,#00H
?MOV TSBIN,#59
?MOV TMBIN,#59
?MOV THBIN,#23
?CLR EX0
?CLR EX1
?CLR ES
?SETB ET0??;開T0、T1中斷
?SETB ET1
?SETB TR0
?SETB TR1
?SETB EA
MAIN1:?MOV R6,#80H??;主處理過程
DISP:?MOV KEYCODE,#00H
?MOV TH1,#00H
?MOV TL1,#00H
?ACALL DISPLY??;調用顯示子程序
?DJNZ R6,DISP
?MOV DPTR,#KEY
?MOV A,KEYCODE??;讀鍵盤值
?JMP @A+DPTR??;按鍵值跳相應處理程序
KEY:?SJMP MAIN1
?SJMP KEY1???????? ;依次為:KEY值+2,4,6,8,因為SJMP占2個字節
?SJMP KEY2???????? ;S1的KEYCODE=02H,S2: KEYCODE=04H
?SJMP KEY3???????? ;S3: KEYCODE=06H, S4: KEYCODE=08H
?SJMP KEY4
KEY1:?CLR TR0???;時計數器加1
?MOV A,THBIN
?CLR C
?ADDC A,#01H
?MOV THBIN,A
?SUBB A,#24??;24D
?JC KEY11
?MOV THBIN,#00H
KEY11:? SJMP MAIN1
?NOP
KEY2:?CLR TR0???;分計數器加1
?MOV A,TMBIN
?CLR C
?ADDC A,#01H
?MOV TMBIN,A
?SUBB A,#60??;60D
?JC KEY21
?MOV TMBIN,#00H
KEY21:? SJMP MAIN1
?NOP
KEY3:?CLR TR0???;秒計數器加1
?MOV A,TSBIN
?CLR C
?ADDC A,#01H
?MOV TSBIN,A
?SUBB A,#60??;60D
?JC KEY31
?MOV TSBIN,#00H
KEY31:? SJMP MAIN1?
?NOP
KEY4:?MOV TH0,#0DCH??;退出校時狀態
?MOV TL0,#00H
?SETB TR0
?SJMP MAIN1

; **********??? 顯示子程序??? **************
???? ORG 0200H??
DISPLY: MOV A,TSBIN??;秒計數器調入A
?MOV B,#0AH
?DIV AB ???;秒計數值÷10 （結果十位存于A，個位存于B）?
?SWAP A
?ORL A,#07H??;顯示秒的十位
?MOV P1,A
?MOV A,#DPS1
?ANL A,OUT
?MOV P3,A
?ACALL DSPDEL??;延時（顯示時）0.5ms
?MOV C,P3.7??;讀S4按鍵狀態
?MOV A,#HIDE
?ANL A,OUT
?MOV P3,A
?JC NP1
?MOV KEYCODE,#08H?;S4按下，鍵盤值＝8?
NP1:?MOV P1,#0F7H??;消隱
?NOP
?NOP
?NOP
?MOV A,B???;顯示秒的個位
?SWAP A
?ORL A,#07H
?MOV P1,A
?MOV A,#DPS0
?ANL A,OUT
?MOV P3,A
?ACALL DSPDEL
?MOV A,#HIDE
?ANL A,OUT
?MOV P3,A
?NOP
?NOP
?NOP
?MOV A,TMBIN??;
?MOV B,#0AH
?DIV AB???;
?SWAP A???;顯示分的十位
?ORL A,#07H
?MOV P1,A
?MOV A,#DPM1
?ANL A,OUT
?MOV P3,A
?ACALL DSPDEL
?MOV C,P3.7??;檢測S2是否按下
?MOV A,#HIDE
?ANL A,OUT
?MOV P3,A
?JC NP2
?MOV KEYCODE,#04H?;S2按下，鍵盤值＝4
?NOP
NP2:?MOV P1,#0F7H??;消隱
?NOP
?NOP
?MOV A,B
?SWAP A???;顯示分的個位
?ORL A,#07H
?MOV P1,A
?;MOV C,KEYPRE
?;MOV P1.3,C
?SETB P1.3
?MOV A,#DPM0
?ANL A,OUT
?MOV P3,A
?ACALL DSPDEL
?MOV C,P3.7??;判斷S3是否按下
?MOV A,#HIDE
?ANL A,OUT
?MOV P3,A
?JC NP3
?MOV KEYCODE,#06H?;若S3按下，鍵盤值＝6
?NOP??
NP3:?MOV P1,#0F7H??;消隱
?NOP
?NOP
?MOV A,THBIN??;
?MOV B,#0AH?
?DIV AB???;
?SWAP A???;顯示時的十位
?JNZ DISPLY1
?MOV A,#0F7H
DISPLY1:ORL A,#07H
?MOV P1,A
?MOV A,#DPH1
?ANL A,OUT
?MOV P3,A
?ACALL DSPDEL
?MOV A,#HIDE
?ANL A,OUT
?MOV P3,A
?NOP
?MOV A,B
?SWAP A???;顯示時的個位
?ORL A,#07H
?ANL A,OUT
?MOV P1,A
?SETB P1.3
?MOV A,#DPH0
?ANL A,OUT
?MOV P3,A
?ACALL DSPDEL
?MOV C,P3.7??;判斷S1是否按下
?MOV A,#HIDE
?ANL A,OUT
?MOV P3,A
?JC NP4
?MOV KEYCODE,#02H?;S1按下，鍵盤值＝2
?NOP
NP4:?MOV P1,#0F7H??;消隱
?NOP
?NOP
?NOP
?RET

;**********??? 延時子程序??? **************8
DSPDEL:?MOV R7,#0FFH??;延時程序0.5ms
?DJNZ R7,$
?RET
?END