Difference between revisions of "Central Processing Unit"

From Computer History Wiki
Jump to: navigation, search
(Add ALU)
m (better cat)
(4 intermediate revisions by the same user not shown)
Line 1: Line 1:
The '''Central Processing Unit''', usually abbreviated as '''CPU''', is the 'brain' of a computer - the unit which controls the operation of the entire computer, by reading instructions from [[main memory]] and executing them.
+
The '''Central Processing Unit''', usually abbreviated as '''CPU''', or simply called a '''processor''', is the 'brain' of a computer - the unit which controls the operation of the entire computer, by reading [[instruction]]s from [[main memory]] and [[execute|executing]] them.
  
Instructions include data-handling instructions (such as arithmetic and logical operations), and control instructions (such as jumps, both conditional and un-conditional).
+
Instructions include data-handling instructions (such as arithmetic and logical operations), and control instructions (such as jumps, both [[conditional branch|conditional]] and un-conditional).
  
The CPU will contain an [[Arithmetic logic unit|ALU]], which is where any computation (arthmetical or logical) is performed. The CPU also usually contains a number of registers (storage for data inside the CPU, instead of in the main memory).
+
The CPU will contain an [[arithmetic logic unit|ALU]], which is where any computation (arthmetical or logical) is performed. The CPU also usually contains a number of [[register]]s (storage for data inside the CPU, instead of in the main memory).
  
One special register indicates where the current/next instruction is to be fetched from (although there have been computers which kept this information in a specific location in main memory). CPUs also typically include registers for holding data which is being worked on: early computers often had only one, called the '''accumulator'''; and there have been computers without any such data registers.
+
One special register, the [[Program Counter]], indicates where the current/next instruction is to be [[fetch]]ed from (although there were early computers which kept this information in a specific location in main memory). CPUs also typically include registers for holding data which is being worked on: early computers often had only one, called the 'accumulator'; and there have been computers without any such data registers.
  
Finally, CPUs usually contain means for controlling the devices attached to the computer; reading data from, and writing data to, them.
+
Finally, CPUs usually contain means for controlling the [[peripheral]]s attached to the computer; reading data from, and writing data to, them.
  
{{stub}}
+
{{semi-stub}}
 +
 
 +
[[Category: Basics]]

Revision as of 12:09, 11 September 2021

The Central Processing Unit, usually abbreviated as CPU, or simply called a processor, is the 'brain' of a computer - the unit which controls the operation of the entire computer, by reading instructions from main memory and executing them.

Instructions include data-handling instructions (such as arithmetic and logical operations), and control instructions (such as jumps, both conditional and un-conditional).

The CPU will contain an ALU, which is where any computation (arthmetical or logical) is performed. The CPU also usually contains a number of registers (storage for data inside the CPU, instead of in the main memory).

One special register, the Program Counter, indicates where the current/next instruction is to be fetched from (although there were early computers which kept this information in a specific location in main memory). CPUs also typically include registers for holding data which is being worked on: early computers often had only one, called the 'accumulator'; and there have been computers without any such data registers.

Finally, CPUs usually contain means for controlling the peripherals attached to the computer; reading data from, and writing data to, them.