Hi,
You have to note the following things,
1)configure the port bit for input on which you will be accepting the a/d values SETB p1.x
2)Read the data sheet carefully for the timmming criteria
3)send the control word information
4)Accept the converted values in carry flag ,bit by bit and rotate the Acc till the count becomes zero,(count indicates the resolution of ur a/d)
for eg. continue:
mov c,p1.X
rlc a
djnz count,continue
If you want to check the values outputed by a/d you can display it on leds or hyperterminal.
Your hex value of a/d will be
x = (i/p voltage * steps)/reference voltage
(this is the general formula for a/d converter)

Pravin