from
The Free On-line Dictionary of Computing (8 July 2008)
central processing unit
CPU
processor
<architecture, processor> (CPU, processor) The part of a
computer which controls all the other parts. Designs vary
widely but the CPU generally consists of the {control unit},
the {arithmetic and logic unit} (ALU), {registers}, temporary
{buffers} and various other logic.
The control unit fetches {instructions} from memory and
decodes them to produce signals which control the other parts
of the computer. These signals cause it to transfer data
between memory and ALU or to activate {peripherals} to perform
input or output.
Various types of memory, including {cache}, {RAM} and {ROM},
are often considered to be part of the CPU, particularly in
modern {microprocessors} where a single {integrated circuit}
may contain one or more processors as well as any or all of
the above types of memory. The CPU, and any of these
components that are in separate chips, are usually all located
on the same {printed circuit board}, known as the
{motherboard}. This in turn is located in the {system unit}
(sometimes incorrectly referred to as the "CPU").
A {parallel computer} has several CPUs which may share other
resources such as memory and peripherals.
The term "processor" has to some extent replaced "CPU", though
RAM and ROM are not logically part of the processor.
List of processors
(http://lldn.timesys.com/complete_list_of_processors).
(2007-04-02)