CURR_NUM_H EQU 30H ;HEX
CURR_NUM_M EQU 32H
CURR_NUM_S EQU 33H
VAR_TIMER EQU 31H ;Soft timer
DAT_74164 bit P0.6
CLK_74164 bit P0.7
DIG_1 bit p0.0
DIG_2 bit p0.1
DIG_3 bit p0.2
DIG_4 bit p0.3
DIG_5 bit p0.4
DIG_6 bit p0.5
;*******************************************
org 0000H
jmp MAIN
org 000BH
jmp interrupt_T0
;*******************************************
org 0030H ;Start program from 0030H
MAIN:
mov P0,#0FFH ;Initialize the port
mov P1,#0FFH
mov P2,#0FFH
mov P3,#0FFH
/*Initilize the var*/
mov CURR_NUM_H,#0
mov CURR_NUM_M,#0
mov CURR_NUM_S,#0
mov VAR_TIMER,#00H
/*Initialize T0*/
mov TMOD,#01H
mov TH0,#0B1H ;20ms,load number
mov TL0,#0E0H
setb TR0 ;Start T0
setb ET0 ;Enable T0 inerrupt
setb EA ;Enable interrupt
;mov IE,#82H ;#10000010B
MAIN_LOOP:
call DISPLAY_NUM ;Display number
jmp MAIN_LOOP
ret
;****************************************************
interrupt_T0:
push acc ;Pay attention to here
push psw
;Reset T0,must be done
;clr TF0 ;auto clear the tag of overflow
mov TH0,#0B1H ;20ms,reload number
mov TL0,#0E0H
inc VAR_TIMER ;Add 20ms
/*If VAR_TIMER=50,then time for 1s */
mov a,VAR_TIMER
cjne a,#50,INT_T0_EXIT
mov VAR_TIMER,#00H
call Time_Clock
INT_T0_EXIT:
pop psw
pop acc
reti
;****************************************************
DISPLAY_NUM:
;A<-A/B,
mov a,CURR_NUM_S
mov b,#0Ah
div ab
mov r0,a
;Display the low value
mov a,b
mov dptr,#TAB_LED
movc a,@a+dptr
call sendTo74164 ;Display the numbet
clr DIG_6
setb DIG_5
setb DIG_4
setb DIG_3
setb DIG_2
setb DIG_1
call DELAY_DISP
;Display the high value
mov a,r0
mov dptr,#TAB_LED
movc a,@a+dptr
call sendTo74164 ;Display the numbet
clr DIG_5
setb DIG_1
setb DIG_2
setb DIG_3
setb DIG_4
setb DIG_6
call DELAY_DISP
mov a,CURR_NUM_M
mov b,#0Ah
div ab
mov r0,a
;Display the low value
mov a,b
mov dptr,#TAB_LED
movc a,@a+dptr
call sendTo74164 ;Display the numbet
clr DIG_4
setb DIG_5
setb DIG_6
setb DIG_3
setb DIG_2
setb DIG_1
call DELAY_DISP
;Display the high value
mov a,r0
mov dptr,#TAB_LED
movc a,@a+dptr
call sendTo74164 ;Display the numbet
clr DIG_3
setb DIG_1
setb DIG_2
setb DIG_5
setb DIG_4
setb DIG_6
call DELAY_DISP
mov a,CURR_NUM_H
mov b,#0Ah
div ab
mov r0,a
;Display the low value
mov a,b
mov dptr,#TAB_LED
movc a,@a+dptr
call sendTo74164 ;Display the numbet
clr DIG_2
setb DIG_5
setb DIG_4
setb DIG_3
setb DIG_6
setb DIG_1
call DELAY_DISP
;Display the high value
mov a,r0
mov dptr,#TAB_LED
movc a,@a+dptr
call sendTo74164 ;Display the numbet
clr DIG_1
setb DIG_5
setb DIG_2
setb DIG_3
setb DIG_4
setb DIG_6
call DELAY_DISP
ret
;*******************************************
;Send data of A to chip 74LS164
sendTo74164:
push 07h
push acc
mov r7,#08 ;send 8 bits
SEND164_LOOP:
clr CLK_74164 ;clear clock-line for reading data
rlc a
mov DAT_74164,c ;move data-bit to data-line
setb CLK_74164 ;send data to 74164
djnz r7,SEND164_LOOP
clr CLK_74164 ;clear clock-line for reading data
pop acc
pop 07h
ret
;****************************************************
Time_Clock:
mov a,CURR_NUM_S
cjne a,#59,INC_NUM_S
mov a,CURR_NUM_M
mov CURR_NUM_S,#00H
cjne a,#59,INC_NUM_M
mov a,CURR_NUM_H
mov CURR_NUM_M,#00H
cjne a,#59,INC_NUM_H
mov CURR_NUM_H,#00H
jmp Time_EXIT
INC_NUM_S:
inc CURR_NUM_S
jmp Time_EXIT
INC_NUM_M:
inc CURR_NUM_M
jmp Time_EXIT
INC_NUM_H:
inc CURR_NUM_H
Time_EXIT:
ret
;****************************************************
;****************************************************
DELAY_DISP:
mov r7,#10
DELAY_DISP_LOOP:
mov r6,#50
djnz r6,$
mov r6,#100
djnz r6,$
djnz r7,DELAY_DISP_LOOP
ret
;****************************************************
;****************************************************
;LED code
TAB_LED:
DB 0C0H,0F9H,0A4H,0B0H,99H,92H,82H,0F8H,80H,90H
;****************************************************
END
