Extensible central processing unit.

摘要

An extensible central processing unit (CPU) (12 or 12'). By modifying the architecture of a new or prior art CPU, a new or prior art CPU can be made extensible so that new instructions can be added in a simple and cost effective manner to meet differing customer needs. The term "extensible" in regard to a CPU is used to mean that new instructions can be added to the CPU simply by adding certain designated circuitry, without the need to significantly change the existing CPU circuitry. In some embodiments, the additional designated circuitry may include control circuitry in the form of CPU control extension circuitry (52 or 152). In some embodiments, the additional circuitry may include non-control circuitry in the form of execution unit extension circuitry (153).