Single chip electronic clock (assembly)

I am very happy today. I wrote this electronic clock in one go (this is the microcontroller experiment tonight. I remember that when I was self-studying microcontrollers last year, I really couldn’t write this. However, this clock is only static and cannot be modified manually. This is still not perfect. If I have time in the future, I will rewrite it, haha)

count equ 9217 ; define 1s count value, for 11.0592 crystal oscillator, delay 10ms

second equ 30h ; define temporary variable area

second_ge equal 31h

second_shi equal 32h

minute equ 33h

minute_ge equal 34h

minute_time 35h

hour equal 36h

hour_ge equal 37h

hour_shi equal 38h

 

       org 0000h

       sjmp main ; enter the main program

       org 0003h

       reti

       org 000bh ;time0 (timer/counter T0 entry address)

       ljmp int_time0 ; jump to interrupt 0 service routine

       org001bh

       reti

       org 0023h

       reti

 

main:     

       mov r0,#0 ; Initialize the program (the initial value of this program is set to 13:33:22)

       mov second,#22

       mov second_ge,#0

       mov second_shi,#0

       mov minute,#33

       mov minute_ge,#0

       mov minute_shi,#0

       mov hour,#13

       mov hour_ge,#0

       mov hour_shi,#0

 

       mov tmod,#00000001b

       mov th0,#high(65536-count); get the high eight bits of data

       mov tl0,#low(65536-count); get the bottom five bits

       clr tf0

       setbea

       setb et0

       setb tr0 ; start timing

loop:      

       lcall digitor_display ;Call the digital tube scanning display program

       sjmp loop ; The program loops here  

 

;Timer 0 interrupt

int_time0:

       push acc

       push psw

 

       clr tf0

       mov th0,#high(65536-count); get the high eight bits of data

       mov tl0,#low(65536-count); get the bottom five bits

       inc r0

       cjne r0,#100,ret_loop ;The second value increases by one

       sjmp second_add

 

second_add: ; Second value processing

       mov r0,#0

       inc second

       mov a,second

       cjne a,#60, ret_loop

       sjmp minute_add

 

minute_add: ; minute value processing

       mov second,#0

       inc minute

       move a,minute

       cjne a,#60, ret_loop

       sjmp hour_add

 

hour_add: ; Hour processing

       mov minute,#0

       inc hour

       move a,hour

       cjne a,#24,ret_loop

       sjmp hour_reset

 

hour_reset:

       mov hour,#0

 

ret_loop:

       pop psw

       pop acc

       reti ;Interrupt return

 

digitor_display: ;digital tube scanning

       push acc

       push psw

       mov a,second

       mov b,#10

       div ab

       mov second_shi,a

       mov second_ge,b

 

       move a,minute

       mov b,#10

       div ab

       mov minute_shi,a 

       mov minute_ge,b

 

       move a,hour

       mov b,#10

       div ab

       mov hour_shi,a

       mov hour_ge,b

 

       mov p1,#11011111b ; Display the units of seconds

       mov a,second_ge

       mov dptr,#table

       movc a,@a+dptr

       mov p2,a

       lcall delay

 

       mov p1,#11101111b ; Display the tens digit of seconds

       mov a,second_shi

       mov dptr,#table

       movc a,@a+dptr

       mov p2,a

       lcall delay

 

       mov p1,#11110111b ; Display the units of minutes

       mov a,minute_ge

       mov dptr,#table

       movc a,@a+dptr

       mov p2,a

       lcall delay

 

       mov p1,#11111011b ; Display the tens digit of minutes

       mov a,minute_shi

       mov dptr,#table

       movc a,@a+dptr

       mov p2,a

       lcall delay

 

       mov p1,#11111101b ; Display the unit digit of the hour

       mov a,hour_ge

       mov dptr,#table

       movc a,@a+dptr

       mov p2,a

       lcall delay

 

       mov p1,#11111110b ; Display the tens place of the hour

       mov a,hour_shi

       mov dptr,#table

       movc a,@a+dptr

       mov p2,a

       lcall delay

       pop psw

       pop acc

 

       ret ; Scanning program returns

 

table: ; Common cathode digital tube scanning code

       DB 3FH ;0

    DB 06H ;1

    DB 5BH ;2

    DB 4FH ;3

    DB 66H ;4

    DB 6DH ;5

    DB 7DH ;6

     DB 27H ;7

    DB 7FH ;8

    DB 6FH ;9

     

delay: mov r4,#5 ; delay function (delay is about 5*255*2=25ms)

l1: mov r5,#0ffh

l2: djnz r5,$

       djnz r4,l1

       ret  

 

       end