programming (Or "op code") The part or parts of a
machinelanguage instruction which determines what kind of action the
computer should take, e.g. add, jump, load, store. In any
within the instruction word contain the op code, others give
For example, in a 32-bit instruction the most significant
eight bits might be the op code giving 256 possible
operations.
For some instruction sets, certain values in the fixed bit
positions may select a group of operations and the exact
operation may depend on other bits within instruction word or
subsequent words.
(1997-02-14)