CPU

in full central processing unit

Principal component of a digital computer, composed of a control unit, an instruction-decoding unit, and an arithmetic-logic unit. The CPU is linked to main memory, peripheral equipment (including input/output devices), and storage units. The control unit integrates computer operations. It selects instructions from the main memory in proper sequence and sends them to the instruction-decoding unit, which interprets them so as to activate functions of the system at appropriate moments. Input data are transferred via the main memory to the arithmetic-logic unit for processing (i.e., addition, subtraction, multiplication, division, and certain logic operations). Larger computers may have two or more CPUs, in which case they are simply called “processors” because each is no longer a “central” unit. See also multiprocessing.

central processing unit

See CPU.

central processing unit

the part of a computer that performs logical and arithmetical operations on the data as specified in the instructions

central processing unit [′sen·trəl ′präs‚əs·iŋ ‚yü·nət]

(computer science)

The part of a computer containing the circuits required to interpret and execute the instructions. Abbreviated CPU.

(architecture, processor)

central processing unit - (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.