Now here is my objective:-

1) Iam using 11.05 KOH crystal as i have to do serial commmunication later and using 12 Mhz will create some problems in braud rates.

2) I have completed designed hardware in working condition for 8 Lines Intercom which will work on Pulse Dialing.

3) Now the only problem is pulse dialing;


When ever a Telephone Set goes off Hook controller gets a High Signal. now how to make it count the incoming pulses:-
according to sepcifications of Pulse Dialing:
if digit 0 is pressed it means 10 pulses per Second.
if 1 is pressed = 1 pulse in 0.1 second...
Inter Digit time is 800 milli second.
Make : Break Ratio is 60 : 40 Milli Seconds. so the pulse is received in 100 Milli Seconds.
Now if i want the controller to do some specific task is digit "21" is pressed controller has to firstly detect these digits in forum of number of zeros ..
2 = two zeros = 2 pulses
1 = 1 zero = 1 pulse
but how to make the controller do this...
i have used the following but its not stable calculation
controller pin P2.0 is considered at this stage it is in High State and looking for logical zero to appear on P2.0
MOV R0,#00D ; setting pulse counter register as zero.
LOOP: P2.0,$ ; Waiting for pulses to come.
INC R0
JMP LOOP