sec equ 30h       ;second register *needed*
to store RTC seconds
min equ 31h      ;minutes register *needed*
to store mins
hour equ 32h     ;hour register *needed*
to store hr
days equ 33h     ;days register *needed*
to store days
date equ 34h     ;date register *needed*
to store date
month equ 35h   ;month register *needed*
to store month
year equ 36h      ;year register *needed*
to store year
alarm equ 37h    ;alarm register *needed*
it is written as alarm but it is used for SQWT register of
your RTC. so is also needed, if you want change the name to
sqwt or something u want.
sig equ 38h       ;signature for data checking in RTC RAM *needed*
needed for checking of valid ram content of RTC
ahour equ 39h   ;alarm hour register
for alarm only can be removed
amin equ 3Ah    ;alarm minute register
for alarm only can be removed
sda equ P1.1     ;Serial data pin *needed*
SDA pin for I2C
scl equ P1.0       ;Serial clock pin *needed*
SCL pin for I2C communication
rw equ p3.6        ;read write pin of LCD
for LCD
en equ p3.5       ;enable pin of LCD
for LCD
rs equ p3.7        ;register select pin of LCD
for LCD
alarm_key equ p3.3   ;Alarm set key
to set alarm.. not needed.. so one key can be removed. and
also the subroutine at location 0x13H
time_key equ p3.2    ;Time ser key *needed*
to set time of clock
increment equ p1.3   ;Increment value *needed*
to set time and alarm, but for u it will only time
decrement equ p1.2   ;Decrement Value *needed*
to set time and alarm, used to reduce the value
alarm_port equ p1.4   ;Alarm Buzzer port
not required
alarm_flag equ 20h    ;flag for alarm
not required
time_flag equ 21h      ;flag for time *needed*
when u press time set key this flag is set.
ampm_flag equ 22h    ;am/pm flag *needed*
used in display am/pm
alarm_on equ 23h       ;Alarm on flag
not required
alarm_off equ 24h       ;alarm off flag
not required
alarm_ring equ 25h      ;alarm ring flag
not required
alarm_hrs equ 58h       ;Alarm hour register
not required
alarm_min equ 59h      ;Alarm Minutes register
not needed
alarm_chk_hour equ 5Ah ;Alarm hour check register
not needed
alarm_chk_min equ 5Bh  ;Alarm min check register
not required
ampm equ 61h           ;AM/PM register *needed*
needed
BELL equ 0h               ;Bell icon *needed*
SPEAKER_OFF equ 1h  ;speaker off icon *needed*
SPEAKER_ON equ 2h    ;speaker on icon *needed*
CLOCK equ 3h           ;clock icon *needed*
OK equ 4h                 ;ok icon *needed*
HEART equ 5h            ;heart icon *needed*
MUSIC equ 6h            ;music icon *needed*

done:
mov sec,#00h ;For more information about the RTC DS1307
mov min,#0h ;Please refer to the datasheet
mov hour,#51h ;21h for 24 hour format
mov days,#01h
mov date,#1h
mov month,#1h
mov year,#05h
;;;LINE MISSING;;;
mov sig,#'~'
mov r6,#07h
mov r0,#30h
mov r1,#00h
acall rtc_ini ;initializing RTC if required

mov alarm,#0

mov r6,#08h

MOV R7,#0FFH
BACK1:MOV TMOD,#01H
MOV TL0,#00H
MOV TH0,#00H
SETB TR0
HER:JNB TF0,HER
CLR TF0
CLR TR0
DJNZ R7,BACK1