• • A Processor is the heart of the Embedded System.
  • • For an embedded system designer knowledge of microprocessor and microcontroller is a must.
  • Two Essential Units:         Operations
  •   Control Unit (CU)           Fetch
  •   Execution Unit (EU)         Execute

Types of Processors

1. General Purpose processor (GPP)

  • • Microprocessor
  • • Microcontroller
  • • Embedded Processor
  • • Digital signal Processor

2. Application Specific System Processor (ASSP)

3. Multi Processor System using GPPs


  • • A microprocessor is a single chip semiconductor device also which is a computer on chip, but not a complete computer.
  • • Its CPU contains an ALU, a program counter, a stack pointer, some working register, a clock timing circuit and interrupt circuit on a single chip.
  • • To make complete micro computer, one must add memory usually ROM and RAM, memory decoder, an oscillator and a number of serial and parallel ports.


  • • A microcontroller is a functional computer system-on-a-chip. It contains a processor, memory, and programmable input/output peripherals.
  • • Microcontrollers include an integrated CPU, memory (a small amount of RAM, program memory, or both) and peripherals capable of input and output.
  • INTEL                                               PIC
  • 8031,8032,8051,8052,8751,8752     8-bit PIC16, PIC18,
  •                                                           16-bit DSPIC33 / PIC24, PIC16C7x
  • MC68HC11


  • • Special microprocessors & microcontrollers often called, Embedded processors.
  • • An embedded processor is used when fast processing fast context-switching & atomic ALU operations are needed.
  • Examples : ARM 7, INTEL i960, AMD 29050.


  • • DSP as a GPP is a single chip VLSI unit.
  • • It includes the computational capabilities of microprocessor and multiply & accumulate units (MAC).
  • • DSP has large number of applications such as image processing, audio, video & telecommunication processing systems.
  • • It is used when signal processing functions are to be processed fast.
  • Examples : TMS320Cxx, SHARC, Motorola 5600xx


  • • ASSP is dedicated to specific tasks and provides a faster solution.
  • • An ASSP is used as an additional processing unit for running the application in place of using embedded software.
  • Examples : IIM7100, W3100A