The purpose of NoTouch is not to ensure that you can procram (that is the pupose of "the backdoor") but to provide a means of programming the chip without "pulling this pin up, this pin down, after 2 seconds ...."

Deepak if you use the latest micros such as P89V51RD2 you don't need to worry about this pin up down etc. etc. and you don't need NoTouch with such chips however backdoor is still required in order to be able to reprogram the chips if boot vector is changed or lost accidently.

I would also like to mention that P89C51RD2 will be obselete very soon. Don't use this chip for any new design instead use P89V51RD2. It has same features as P89C51RD2 + some other good features.

Regards,
Prahlad Purohit