US 6,477,658 B1 · Microprocessor with variable clock operation

Abstract

A microprocessor with a variable clock operation, which is operative at a highest speed as well as a lowest speed, within a maximum performance range of the microprocessor is disclosed. The invention includes a microprocessor having a Critical Path Operation (CPO) block that is operative at a speed corresponding to an external clock signal; a decision circuit for deciding an operation state of the microprocessor, according to a test result of the CPO block in the microprocessor; a MUX unit for selecting a signal from either a signal from the decision circuit or an external signal, selecting a signal intended to control, and forwarding the selected signal; a controlling unit for receiving a signal from the MUX unit for providing a control signal for varying a clock signal; and a PLL circuit for varying the clock signal in response to the control signal from the controlling unit for applying a varied clock signal to the microprocessor.

Claims12

Dependent claims

A microprocessor with a variable clock operation cycle, comprising:

a microprocessor comprising a Critical Path Operation (CPO) block configured to conduct at least one microprocessor operation using a current clock signal, wherein the microprocessor is adapted to be operated at a speed corresponding to a controllably variable clock signal, wherein the controllably variable clock signal sets the current clock signal;
a decision circuit configured to receive the current clock signal and an output signal from the CPO to determine an operation completion status of the at least one microprocessor operation;
a controlling unit coupled to the decision circuit and configured to provide a control signal based on the operation completion status of the at least one microprocessor operation;
and,
a Phase Locked Loop (PLL) circuit configured for varying the controllably variable clock signal received by the microprocessor in accordance with the control signal.

2 more elements

Dependencies are inferred from the claim text.

Microprocessor with variable clock operation

Life of this patent

Microprocessor with variable clock operation

Life of this patent

Abstract

Claims12