Microcontroller

A microcontroller is  a complete microprocessor system ,containing of microprocessor ,limited amount of ROM RAM and parallel I/O ports ,built on a single integrated circuit .
Microcontroller is in fact a microcomputer ,but it is called so because it is used to perform control functions .
Expanded features of 8052 over 8051 microcontroller are as follows:
a) ROM  :- Microcontroller 8052 has 8 KB bytes onboard ROM or EPROM whereas 8051 has 4 KB  bytes  of ROM .
b)  RAM  :-    Microcontroller 8052 has 256 bytes of onboard RAM whereas 8051 has 128 bytes of RAM.
c)   Time event counter :- 8052 has an extra 16 bit time event counter whereas 8051 has a dual 16 bit time event counter.