"

Fundamentals of Microprocessors and Microcontrollers

1.1 Definitions and Basic Concepts

Microprocessor: A microprocessor is a computer processor on a single integrated circuit (IC) that contains the arithmetic, logic, and control circuitry required to perform the functions of a computer’s central processing unit (CPU). It is designed to execute a set of instructions to perform tasks such as arithmetic operations, data movement, and control operations. The microprocessor is the brain of a computer system, capable of fetching, decoding, and executing instructions from memory.

IBM PCMCIA Data-Fax Modem V.34 FRU 42H4326 - ZiLOG microprocessor Z80182-9359

Figure 1: Microprocessor (“IBM PCMCIA Data-Fax Modem V.34 FRU 42H4326 – ZiLOG microprocessor Z80182-9359” by Raimond Spekking is licensed under CC BY-SA 4.0.)

Microcontroller: A microcontroller is a compact integrated circuit designed to govern a specific operation in an embedded system. It includes a processor, memory (RAM, ROM, EPROM), and input/output (I/O) peripherals on a single chip. Microcontrollers are used in automatically controlled devices such as automobile engine control systems, medical devices, remote controls, office machines, appliances, power tools, toys, and other embedded systems.

Arduino microcontroller / Arduino Uno microcontroller ATmega328 / Arduino Mega 2560 / Arduino Nano ATmega328 / Arduino Pro Mini ver.3.3V ATmega328 / Photo by Arkadiusz Sikorski http://www.arq.pl/

Figure 2: Microcontroller (Arduino microcontroller / Arduino Uno microcontroller ATmega328 / Arduino Mega 2560 / Arduino Nano ATmega328 / Arduino Pro Mini ver.3.3V ATmega328 / Photo by Arkadiusz Sikorski http://www.arq.pl/” by Arkadiusz Sikorski is licensed under CC BY 2.0.)

1.2 Historical Development

The development of microprocessors and microcontrollers has been a significant milestone in the evolution of computing technology.

Microprocessors:

  • 1971: Intel introduced the first microprocessor, the Intel 4004, a 4-bit processor capable of performing basic arithmetic and logic operations.
  • 1972-1978: The second generation saw the development of 8-bit microprocessors like the Intel 8008 and 8080, which were used in early personal computers.
  • 1978-1980: The third generation introduced 16-bit processors such as the Intel 8086 and Motorola 68000, which offered improved performance and capabilities.
  • 1981-1995: The fourth generation brought 32-bit processors like the Intel 80386, which became popular for both control applications and number-crunching operations.
  • 1995-Present: The fifth generation includes 64-bit processors like the Intel Pentium series, which are used in modern computers and offer high performance and speed.

Microcontrollers:

  • 1971: The first microcontroller, the TMS 1000, was developed by Texas Instruments, combining a processor, memory, and I/O on a single chip.
  • 1974: Intel introduced the 8048, which became widely used in embedded systems such as PC keyboards.
  • 1993: The introduction of EEPROM memory allowed for electrically erasable and programmable microcontrollers, facilitating rapid prototyping and in-system programming.
  • Present: Modern microcontrollers are highly integrated and used in a wide range of applications, from consumer electronics to industrial automation.

1.3 Comparison Between Microprocessors and Microcontrollers

Feature Microprocessor Microcontroller
Components CPU only CPU, memory, I/O ports, peripherals
Purpose General-purpose computing Specific control tasks in embedded systems
Memory External On-chip
I/O Ports External On-chip
Architecture Von Neumann Harvard
Cost Higher Lower
Power Consumption Higher Lower
Applications Personal computers, servers, complex systems Home appliances, automotive systems, toys
Processing Power Higher Lower
Development Complexity More complex Simpler

1.4 Basic Functions and Applications

Basic Functions of Microprocessors:

  • Fetch, Decode, Execute: The microprocessor fetches instructions from memory, decodes them to understand the required operations, and executes them.
  • Arithmetic and Logic Operations: Performs basic arithmetic operations (addition, subtraction) and logic operations (AND, OR, NOT).
  • Data Transfer: Moves data between different parts of the system, such as from memory to registers.
  • Control Operations: Manages the control signals to coordinate the activities of the system components.

Basic Functions of Microcontrollers:

  • Embedded Control: Designed to perform specific control tasks within an embedded system.
  • I/O Operations: Interfaces with external devices through built-in I/O ports.
  • Timers and Counters: Includes peripherals for timing and counting operations.
  • Analog to Digital Conversion: Converts analog signals to digital form for processing.

Applications:

  • Microprocessors: Used in personal computers, servers, high-performance computing systems, and complex industrial controllers.
  • Microcontrollers: Found in household appliances (washing machines, microwaves), automotive systems (engine control units), medical devices (ECG machines), and consumer electronics (remote controls, digital cameras).

Deepen your understanding: Watch the accompanying lecture video to get deeper into the concepts covered in the reading.

License

Icon for the Creative Commons Attribution 4.0 International License

Introduction to Microcontrollers Copyright © 2024 by Lake Washington Institute of Technology is licensed under a Creative Commons Attribution 4.0 International License, except where otherwise noted.