Microcontrollers and Microprocessors

Chapter 5: Microcontrollers and Microprocessors

5.1 Introduction

  • Overview of embedded systems.

  • Focus on microcontrollers: Integral part of embedded systems (independent/dependent).

  • Definition: Microcontroller = Integrated circuit (IC) containing CPU, memory, I/O ports.

  • Applications: Consumer electronics, appliances, automotive systems, industrial control.

  • Term: Microcontroller Unit (MCU).

5.2 Microcontroller Architecture

  • MCU is a small computer on a single VLSI chip.

  • Components: One or more CPUs, memory (RAM/ROM), I/O peripherals.

  • Architecture: Generally Harvard architecture (separate data and instruction memory).

  • Key components: CPU, memory, I/O ports, clock oscillator.

  • Built-in peripherals: Timers, ADCs, DACs, interrupt controllers.

  • Classification based on CPU size: 8-bit, 16-bit, 32-bit microcontrollers.

5.3 Microcontroller History & Invention

  • Origin: Intel's 4004 (1970s) - First widely available microcontroller.

  • Evolution: Expansion to various microcontroller families (Motorola 68HC11, Intel 8051).

  • Development in the 1990s with advanced capabilities (e.g., PIC microcontroller).

  • Modern applications: IoT devices, medical equipment, industrial automation.

5.4 Microcontroller Types

  • 5.4.1 8-bit Microcontrollers:

    • Suitable for simple control tasks (e.g., remote controls).

    • Examples: PIC, 8051.

  • 5.4.2 16-bit Microcontrollers:

    • Used in more complex applications (e.g., industrial automation).

    • Examples: dsPIC, 68HC11.

  • 5.4.3 32-bit Microcontrollers:

    • High-performance applications (e.g., industrial automation, medical equipment).

    • Examples: PIC32, ARM Cortex-M.

  • 5.4.4 64-bit Microcontrollers:

    • High memory capacity for complex algorithms; used in server, industrial automation.

  • 5.4.5 Microcontrollers with Built-in Memory:

    • Applications needing data storage (e.g., consumer electronics).

  • 5.4.6 Microcontrollers with Built-in Peripheral:

    • Used in communication applications (e.g., USB, IoT devices).

5.5 Microcontrollers Working

  • Stages of Operation:

    • 5.5.1 Input: Receives data from sensors; converts analog to digital using ADC.

    • 5.5.2 Processing: Executes program instructions based on stored data.

    • 5.5.3 Output: Sends processed data to devices using DAC and output ports.

5.6 Microcontroller and Microprocessors

  • Differences:

    • Microcontroller: Integrated circuit (includes CPU, memory, I/O).

    • Microprocessor: CPU only; requires external components.

    • Use: Microcontrollers for embedded systems; microprocessors for general computing.

5.7 Advantages of Microcontrollers

  • Power Consumption: Low energy use, ideal for portable devices.

  • Flexibility: Programmable for various tasks.

  • Applications: Automotive systems, industrial control, household appliances.

5.8 Microcontroller Companies

  • Notable manufacturers: Microchip Technology, Texas Instruments, Arduino, NXP Semiconductors, STMicroelectronics, Atmel, Renesas, Cypress, Silicon Laboratories, Broadcom, Maxim Integrated.

  • Market factors: Performance, power consumption, cost, features.

  • Future focus: Arduino microcontrollers for embedded systems.