Difference between revisions of "Instruction"
From Computer History Wiki
(Especially early ones) |
(→See also: +Instruction set) |
||
| Line 6: | Line 6: | ||
{{semi-stub}} | {{semi-stub}} | ||
| + | |||
| + | ==See also== | ||
| + | |||
| + | * [[Instruction set]] | ||
[[Category: CPU Basics]] | [[Category: CPU Basics]] | ||
Latest revision as of 18:50, 3 June 2023
An instruction is, at the highest level of abstraction, the smallest unit of computation which a programmer can direct the CPU to perform.
In more practical terms, the CPU operates by fetching items from main memory; each item contains a single directive for the CPU (e.g. add the contents of one register to another, or move a unit of data from a register, to main memory) - those items are instructions. (An instruction is usually a word, but on some CPUs, multiple instructions could be packed in each word, while on others, some instructions took multiple words.)
Some early computers used the alternative term order for instructions.
