Introduction to Microcontroller and Microprocessors, role of Embedded Systems, open source embedded platforms

Differences between μC and μP





CPU is stand-alone, RAM, ROM, I/O & timer are separate.

CPU, RAM, ROM, I/O & timer all are on single chip.

Designer can decide amount of RAM, ROM & I/O ports.

Fixed amount of on-chip RAM, ROM & I/O ports.

High processing power

Low processing power

High power consumption

Low power consumption

Typically 32/64 bit

8/16 bit

General purpose

Single purpose (control oriented)

Less reliable

Highly reliable

Examples:  8086, 8085

Examples: 8051, ATmega328P

Embedded System

Any computing system other than Desktop or PC which performs a dedicated function.

Ex. Washing Machine,Printer


Microcontrollers for embedded systems

  • In the literature discussing microprocessors, we often see the term embedded system. Microprocessors and microcontrollers are widely used in embedded system products.
  • An embedded product uses a microprocessor (or microcontroller) to do one task and one task only.
  • A printer is an example of embedded system since the processor inside it performs only one task; namely, getting the data and printing it. Contrast this with a Pentium-based PC (or any x86 IBM-compatible PC).
  • A PC can be used for any number of applications such as word processor, print server, bank teller terminal, video game player, network server, or internet terminal. Software for a variety of applications can be loaded and run. Of course the reason a PC can perform myriad tasks is that it has RAM memory and an operating system that loads the application software into RAM and lets the CPU run it.
  • In an embedded system, there is only one application software that is typically burned into ROM.
  • An x86 PC contains or is connected to various embedded products such as the keyboard, printer, modem, disk controller, sound card, CD-ROM driver, mouse, and so on.
  • Each one of these peripherals has a microcontroller inside it that performs only one task. For example, inside every mouse there is a microcontroller that performs the task of finding the mouse position and sending it to the PC. Table 1-1 lists some embedded products.

Role of μC in Embedded System Market

A microcontroller is a small computer on a Single Integrated Circuit containing a processor core, memory and programmable input/ output peripherals. Program memory in the form of NOR flash or OTPROM is also often included on chip, as well as a typically small amount of RAM.

Microcontrollers are designed for embedded applications, in contrast to the microprocessors used in personal computers or other general purpose applications.

Role of μC:

  1. They satisfies market needs, have so many features, and are designed for satisfying embedded system needs. That means perform functions only for its (embedded systems) purpose.
  2. They provide wide marketing area for embedded systems.
  3. They upgrade standard of embedded system market.
  4. It simplifies the complexity of market needs.
  5. They help in innovations (standard applications).
  6. Power consumption factor is more favorable: They require or consume less energy, which is the main factor, to satisfy user needs.
  7. Heart of the embedded system: Microcontroller is the heart of embedded system, because it gives life for embedded system applications. The invention of microcontroller made an unexpected changes in embedded technology.
  8. Applications have high perfection: Perfection in embedded system applications by the invention of microcontroller.
  9. Reduces cost of embedded system applications: Embedded systems are designed to do some specific task in contrast to a general purpose computer which is used for multiple tasks.
  10. It makes embedded systems flexible in market.
  11. Make effective use (due to cost): Many embedded systems more microcontrollers, which have self sufficiency and cost-effectiveness.
  12. Embedded systems are typically far cheaper than general-purpose personal computers.
  13. Interconnection: Once the hardware is decided upon, an interconnection fabric must be devised.
  14. Low power design: A general goal in embedded systems, low power design is particularly important for SoC.
  15. Testing and verification: The increase in complexity combined with a lack of knowledge about individual IP blocks that comes with reuse techniques leads to problems in adequate testing and verification of the complete systems.
  16. Energy management: Efficient metering systems helps in energy conservation.


  • Notes by Prof. Sujit Wagh
Created by Sujit Wagh on 2017/08/19 12:54