Abstract: A method of providing critical circuits in a library of circuits, whereby such critical circuits allows designers to apply modifications to them in a controlled manner such that the changes are easy to implement and virtually guaranteed to be correct. The invention comprises a method of performing limited modifications to such critical circuits to alter its characteristics in a controlled manner, and thereafter checking the resulting modified circuit with a circuit simulator for conformance to predetermined specifications that have been assembled for this library critical circuit.

Abstract: A circuit for reducing power in an on-chip cache memory on a microprocessor chip is implemented by dynamically controlling power applied to individual memory sections. Individual sections of memory are isolated from a fixed power supply by inserting one or more switches between GND and a negative connection of an individual memory section or by inserting one or more switches between VDD and a positive connection of an individual memory section. If a memory section is not accessed for a defined time, a PMU (Performance Monitor Unit) detects it and the power to that section is switched off, saving power. In addition, a software application may send information to the PMU to select the amount of cache memory needed for the particular software application.

Abstract: A system and method for optimizing the power consumption or the access time of a subdivided cache memory system is described. An adjustable voltage power supply provides power to a section of a subdivided cache. The voltage to this section may be increased, yielding a faster access time. The voltage to this section may also be decreased. Decreasing the voltage to this section decreases the power consumed by the cache memory system.

Abstract: A method of providing critical circuits in a library of circuits, whereby such critical circuits allows designers to apply modifications to them in a controlled manner such that the changes are easy to implement and virtually guaranteed to be correct. The invention comprises a method of performing limited modifications to such critical circuits to alter its characteristics in a controlled manner, and thereafter checking the resulting modified circuit with a circuit simulator for conformance to predetermined specifications that have been assembled for this library critical circuit.