3.2.7 Outline the function           of a          microprocessor.

Pentium 4, K6, PowerPC are common types of (micro)processor.

It is important to understand that a microprocessor will need both volatile (RAM) and non-volatile (ROM) memory for its operation.

A good site with more detailed info and examples is HowStuffWorks.

What it is

When we looked at the CPU we gave a diagram as follows:

The CU and the ALU form a discrete unit or integrated circuit (sometimes known as an ic or a chip ) which is the microprocessor .

There are many different kinds of microprocessor (sometimes shortened to processor), each one has its own instruction set (commands which it is designed to carry out). Each microprocessor also has registers in a fixed size (the word size, typically 64 or 128 bits these days).

The addition of Primary Memory makes a programmable machine since different programs can be loaded and run through the microprocessor.

However, often a microprocessor is emedded into another machine and used to run a fixed program (usually held in ROM ). Examples are cameras, washing machines, air conditioners, televisions, stereos, cars, watches, calculators, mobile phones and so on and so on.

In a washing machine, for example, the program controls the inlet and outlet valves, the heating elements and reads data from an external panel that has various controls.

The microprocessor program needs information from sensors (temperature sensors, timers, etc) and therefore needs to store temporary information, it needs some form of RAM for this purpose.

A microprocessor might be fitted with RAM to hold temporary data from sensors , have various output ports to which actuator interfaces can be attached. A general purpose programmable micorprocessor of this type is called a microcontroller and is the workhorse of our information age.

Microcontrollers are built into lots and lots of everyday things. Not a day goes by when you don't interact with a large number of microcontrollers, the devices you are using now (mouse, keyboard, display card, disc drive) are probably controlled by these units.

A microcontroller in a car might measure the fuel consumption, operate the heating/cooling, measure the rotation of the wheels to see if there is a skid (ABS) or operate the airbag on a sudden decceleration.

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related: [ Common core home | previous: memories | next: peripherals ]

Some texts, particularly in the USA don't include the IAS (primary memory) in the CPU.

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