Microprocessor


  • A microprocessor is similar to a CPU, but has significantly less primary memory.
  • Numerous devices we use daily have one or more microprocessors inside of them. Examples include: TVs, cars, beamers, watches, phones, ovens, CD players, etc.
    • Ex. in a washing machine a microprocessor might be used to control the temperature, water level, spin speed and washing time
      • Inputs: control buttons on machine; temperature, water level and rotational speed sensor
      • Outputs: electronic signals to other internal hardware components (ex. water pump), LCD screens, sounds, LEDs
  • A microprocessor has a single program stored in non-volatile memory, but also has some volatile registers to store data at runtime.
    Atmel_atmega32_mikrokontrolleri.jpg
    An example of a commonly used microprocessor (ATmega32 in this case)
    • This differentiates microprocessors from CPUs, since CPUs don't have a single program stored in non-volatile memory.
  • Microprocessors are like CPUs but cannot change their programs.
  • When the first microprocessor was introduced, it had about 6,000 transistors. Today, a microprocessor can have several Billion transistors.

You can differentiate microprocessors in:
  • Instruction set: The set of instructions that the microprocessor can execute
  • Bandwidth: The number of bits processed in a single instruction
  • Clock speed: the clock speed determines how many instructions per second the processor can execute (usually measured in MHz)

There are two types of microprocessors:
microsprocessor.jpg
An example of an uncommon microprocessor

  • RISC's (Reduced Instruction Set Computer)
    • Processes things faster than a CISC
    • Smaller instruction set than a CISC
  • CISC's (Complex Instruction Set Computer)
    • Processes things slower than a RISC
    • Larger instruction set than a RISC

A microprocessor incorporates most or all of the functions of a CPU on a single chip.
Microprocessors use the ALU to do arithmetic calculations.



Edited by Jocbe
Last updated: 7. October 2010