Hi Shahzad,

The (external) hardware is identical in the 8051 and 8052, so you do not need to make changes to your circuit.

Whether or not you need to change your software is a different matter. If you want to use the extra's that the 8052 offers, then yes! The program that now runs on the 8051 will work just fine on the 8052, but it does not make much sense to go for a 'bigger' controller if you don't change the software as well.

Best regards,
Rob.