Solution:

• There are a huge variety of microcontrollers.

• They can be classified on following: Internal bus width: 4 bit; 8 bit; 16 bit; 32 bit and 64 bits .

• As per the BUS width nothing but the number of parallel wires, the microcontrollers are divided as: 8-Bit, 16-bit, 32-bit etc?

• The objective of this is to transfer the data or address inside the processor between the different chip like RAM, ROM, BUS Controller etc. in high speed it needs a number of parallel wires for communication.