Delay Controller Program Using 89C2051 Single Chip Microcomputer

;***************************************************
;* Delay controller made of single-chip microcomputer 89C2051 *
;* T0 and TT0 are combined to form a second pulse generator *
;* TSBIN is a second counter (binary, 0~60); 21H unit *
;* TMBIN is a minute counter (binary, 0~60); 22H unit *
;* THBIN is a hour counter (binary, 0~24); 23H unit *
;* KEYCODE is the keyboard value; 29H unit *
;* KEYPRE is the key mark word; PSW.5 *
;* When the countdown reaches 00H00M00S, P3.0, P3.1 terminals output *
;* inverted signals. *
;* S1----Time button; S2－Minute button; *
;* S3－Second button; S4－Exit time synchronization *  
;****************************************************

 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 ;Blanking word

 ORG 0000H
 AJMP MAIN

 ORG 000BH
 SJMP I_T0

 ORG 001BH
I_T1: AJMP MAIN1
 RETI

;*********** T0 interrupt service ***********
 ORG 0030H
I_T0: PUSH A CC
 PUSH PSW 
 MOV TH0,#0DCH ;0.01s time, constant factor is DC00H
 ;MOV TL0,#00H 
 CLR C
 MOV A,TMSBIN
 SUBB A,#01H
 MOV TMSBIN,A
 MOV R3,TT0  
 DJNZ R3,I_T01 ;Interrupt times <100 (0.01S per interrupt), transfer out
 CPL KEYPRE
 MOV R3,#100 ;Interrupt times = 100 times, restart the next count
 MOV TMSBIN,#100
 CLR C
 MOV A,TSBIN ;Second counter plus 1
 SUBB A,#01H
 MOV TSBIN,A
 ;SUBB A,#60 ;Second counter>59? Y, second counter = 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 ;Minute counter plus 1
 SUBB A,#01H
 MOV TMBIN,A
 JNC I_T01
 MOV A,THBIN
 JZ I_T01
 MOV TMBIN,#59
 CLR C
 MOV A,THBIN ;Hour counter plus 1
 SUBB A,#01H
 MOV THBIN,A
 ;SUBB A,#24 ;Hour counter>23? Y, hour counter＝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 outputs low level
 MOV P3,OUT
 MOV SP,#40H ;Initialize stack pointer  
 MOV TMOD,#11H ;T0, T1 work as 16-bit timer
 MOV TT0,#100
 MOV TH0,#0DCH ;T0 initial value
 MOV TL0,#00H
 MOV TH1,#00H ;T1 initial value
 MOV TL1,#00H
 MOV TSBIN,#59
 MOV TMBIN,#59
 MOV THBIN,#23
 CLR EX0
 CLR EX1
 CLR ES
 SETB ET0 ;Open T0, T1 interrupt
 SETB ET1
 SETB TR0
 SETB TR1
 SETB EA
MAIN1: MOV R6,#80H ;Main processing
DISP: MOV KEYCODE,#00H
 MOV TH1,#00H
 MOV TL1,#00H
 ACALL DISPLY ;Call display subroutine
 DJNZ R6,DISP
 MOV DPTR,#KEY
 MOV A,KEYCODE ;Read keyboard value
 JMP @A+DPTR ;Press key value to jump to corresponding processing program

KEY: SJMP MAIN1
 SJMP KEY1 ; In sequence: KEY value + 2, 4, 6, 8, because SJMP occupies 2 bytes
 SJMP KEY2 ; S1's KEYCODE = 02H, S2: KEYCODE = 04H
 SJMP KEY3 ; S3: KEYCODE = 06H, S4: KEYCODE = 08H
 SJMP KEY4
KEY1: CLR TR0 ; Hour counter plus 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 ; Minute counter plus 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 ;Increase the second counter by 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 ;Exit the time calibration state
 MOV TL0,#00H
 SETB TR0
 SJMP MAIN1

; ********** Display subroutine **************
     ORG 0200H  
DISPLY: MOV A,TSBIN ; Transfer the second counter into A
 MOV B,#0AH
 DIV AB ; Count the second value ÷ 10 (the result is stored in A for tens and in B for ones) 
 SWAP A
 ORL A,#07H ; Display the tens digit of the second
 MOV P1,A
 MOV A,#DPS1
 ANL A,OUT
 MOV P3,A
 ACALL  DSP DEL ; Delay (when displaying) 0.5ms
 MOV C,P3.7 ; Read the status of S4 key
 MOV A,#HIDE
 ANL A,OUT
 MOV P3,A
 JC NP1
 MOV KEYCODE,#08H ; S4 is pressed, keyboard value = 8 
NP1: MOV P1,#0F7H ; Blanking
 NOP
 NOP
 NOP
 MOV A,B ; Display the ones digit of the second
 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 ;Display the tens digit of
 minutesORL A,#07H
 MOV P1,A
 MOV A,#DPM1
 ANL A,OUT
 MOV P3,A
 ACALL DSPDEL
 MOV C,P3.7 ;Check if S2 is pressedMOV
 A,#HIDE
 ANL A,OUT
 MOV P3,A
 JC NP2
 MOV KEYCODE,#04H ;S2 is pressed, keyboard value＝4
 NOP
NP2: MOV P1,#0F7H ;Hide
 NOP
 NOP
 MOV A,B
 SWAP A ;Display the ones digit of
 minutesORL 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 ;Judge whether S3 is pressed
 MOV A,#HIDE
 ANL A,OUT
 MOV P3,A

 JC NP3
 MOV KEYCODE,#06H ;If S3 is pressed, the keyboard value = 6
 NOP  
NP3: MOV P1,#0F7H ;Hide
 NOP
 NOP
 MOV A,THBIN ;
 MOV B,#0AH 
 DIV AB ;
 SWAP A ;Tens digit when displayed
 JNZ DISPLY1
 MOV A,#0F7H
DISPLY1:ORL A,#07H
 MOV P1,A
 MOV A,#DPH1
 ANL A,OUT
 MOV P3,A
 ACALL  DSP DEL
 MOV A,#HIDE
 ANL A,OUT
 MOV P3,A
 NOP
 MOV A,B
 SWAP A ;Ones digit when displayed
 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 ;Judge whether S1 is pressed
 MOV A,#HIDE
 ANL A,OUT
 MOV P3,A
 JC NP4
 MOV KEYCODE,#02H ;S1 is pressed, keyboard value = 2
 NOP
NP4: MOV P1,#0F7H ;Hide
 NOP
 NOP
 NOP
 RET

;********** Delay subroutine **************8
DSPDEL: MOV R7,#0FFH ; Delay program 0.5ms
 DJNZ R7,$
 RET
 END