Michael Karas,,
i have said it before and i say it again when it comes to get really help Michael Karas is one ...like if there is any competition for voting the most helpful person on this forum..its you Man...
iam not saying this coz you have placed some sort of coding its becauase you help.. really i have no words to thank you but please if you can only suggest something about the following that can really clear my concepts..

I also thank all of you for helping me ..really Pulse Dialing is a Tough Job....and the off-hook thing is just i said to make you people think what iam doing..still iam unable to make controller detect the pulse but iam working on it using the Michael Karas method of filtering but if any one can come up with some other idea do post it...it will also help future people in need to learn...

Actually the coding should be such that if we connect any Pulse Dialing Telephone Set with the exchange it works perfectly...
there has to be some specification like i found one but its not working as far iam trying..

60 Milli Second Make
40 Milli Second Break
800 Milli Second Inter Digit Space

Now at this stage iam only considering one telephone set...but its not working at all..


The telephone is connected at P2.0

Now when the set goes off hook p2.0 gets High

at this stage controller connect Y0 with X2 of MT8816 so that Dial Tone appears in telephone set.

now controller wait for digit dialing
if and only if digit "2" is dialed then only controller disconnect the dial tone other wise do nothing...

now iam only doing this as a experiment so that i can have some idea about pulse dialing..but this is not working can some one please suggest some thing about this:-

ORG 00h
LJMP MAIN


ORG 0030H
MAIN:
MOV P3,#00000000B ;STROBE at p3.7
MOV P2,#00000000B ;RESETING THE PIN
MOV P1,#00000000B ;RESETING THE PIN

OFF: JNB P2.0,OFF ;WAITING FOR OFF-HOOK
MOV P1,#10010000B ;ADDRESS LINE TO CONNECT Y0 WITH X2 FOR DIAL TONE
SETB P3.7 ;STROBE IS SET HIGH
CALL PULSE_DIAL
DO: SJMP DO


PULSE_DIAL:
MOV R0,#00D ;PULSE COUNTER REGISTER

WAITING: JB P2.0,WAITING ;WAITING FOR DIALING
CALL DELAY_60MS ;MAKE =60 MILLI SECOND
JNB P2.0,MAIN ;CHECKING IS USER CONNECTED OR NOT
CALL DELAY_40MS ;BREAK = 40 MILLI SECONDS
INC R0 ;COUNT PULSES
JB P2.0,TASK ;IF USER IS STILL ON HOOK PERFORM THE TASK
JMP MAIN


DELAY_60MS:
MOV TMOD,#01H ;16 BIT
MOV TH0,#15H
MOV TL0,#A0H ;error is occuring here
SETB TR0
timer2: JNB TF0,timer2
CLR TR0
CLR TF0
RET

DELAY_40MS:
MOV TMOD,#01H ;16 BIT
MOV TH0,#63H
MOV TL0,#C0H ; error is occuring here
SETB TR0
timer3: JNB TF0,timer3
CLR TR0
CLR TF0
RET


TASK:
CJNE R0,#02D,DO
CLR p3.7 ;disconnecting dial tone
END