2.Microcontrollers/Microprocessors

         The microprocessor/microcontroller is very very basic of embedded systems.Nowadays all latest advanced equipments having microcontroller/microprocessor.A designer/Architect of chip should know what types of components he needs, ways to reduce production costs and product reliable.

Blocks in microprocessor/controller:

• CPU: Central Processing Unit
• I/O: Input /Output
• Bus: Address bus & Data bus
• Memory: RAM & ROM
• Timer
• Interrupt
• Serial Port
• Parallel Port 

Microprocessor:

• CPU for Computers
• Does not have RAM, ROM, I/O on CPU chip itself
• Example：Intel’s x86, Motorola’s 680x0

A microprocessor  is a general purpose central processing unit of a digital computer

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            A very popular general term known as "A chip on a computer".Processors have most of their opcodes moving data from external memory to the CPU.

Microcontroller:

                      A micro controller is a true computer on a chip.A very popular general term known as "A computer on a chip".         The prime use of a microcontroller is to control the operation of a machine using fixed programs that is stored in ROM that doesn't change over the life time of the system.
Example:
Atmel, philips Microcontrollers..

Let us see about "8051 Microcontroller" in detail.