"I am looking forward to know how to drive a 7-segment display using 8051"

You didn't say how many digits!

We're assuming that you want several digits, and want 'em multiplexed.

I have just done a design for a Client using the Triscend E5 where I did all the multiplexing in the E5's programmable logic - so all the software had to do was write the appropriate values to the appropriate elements of an array, and the "hardware" did all the rest!

The only external components required (apart from the LEDs!) were the current-limiting resistors and digit drive transistors (depending on your brightness requirements & the efficacy of your LEDs, you might not even need them).

In this project, the encoding of the segment patterns was done in software, but the Triscend FastChip software includes an IP module for the standard digit encodings, if you prefer.