i want the details about how to interface the ADC082S101 with 89C51. and program also i will appreciate if it will be in C language.
All the necessary details will be provided in:
1. The Datasheet for the ADC082S101, plus
2. The Datasheet for the specific "89C51" that you intend to use.
For additional supporting materials, see the manufacturer's website(s) for application notes, sample code, reference designs, etc...
If you can't or don't want to do it yourself, see: http://www.keil.com/condb