| All these components of a microprocessor
are fabricated of a single IC. Such ICs are coupled to build a computer.
Three minimum ICs needed to make up a microprocessor are the CPU, memory,
and peripheral IC.
CPU (Central Processing Unit)
The CPU forms the nucleus of any computer by executing
instructions. Microprocessors are grouped into 4-bit, 8-bit, 16-bit,
and 32-bit microprocessors according to the length of bits they can handle
at a time. A 4-bit microprocessor can handle four binary digits in
a single instance of calculation, but as many as eight digits in two instances
and 16 in four instances.
The microprocessor is also known as a "MPU (microprocessing
unit)", "microprocessor", or simply "processor."
Memory (Memory)
A device on which instructions and data are stored.
Without memory, programs and data cannot be used. In a microprocessor,
ROM (read-only memory) and RAM (random access memory) are used.
Input device (Input)
A data input device. The keyboard and mouse of
a PC, for example, are data input devices. With a built-in controller,
switches and sensors are input devices.
These input devices cannot be directly connected to a CPU, but
they must be attached to the CPU by way of a "peripheral IC," containing
connection circuitry. Depending on the kind of input device to be
connected to the CPU, an appropriate peripheral IC is used.
Output device (Output)
A data output device. The display and printer
of a PC, for example, are data output devices. With a built-in controller,
display LEDs, motors, heaters and so on are output devices. Like
input devices, output devices are attached to a CPU by way of a "peripheral
IC." Depending on the kind of output device to be connected to the
CPU, an appropriate peripheral IC is used.
Input devices and output devices are collectively called "peripherals." |
