Patent ID: 6388483
Filing Date: 2002-05-14
Classification: H03K

Abstract:
A semiconductor integrated circuit comprising:a logic circuit comprising MIS transistors formed on a semiconductor substrate which implements a certain logical processing; an oscillation circuit comprising MIS transistors formed on said semiconductor substrate which produces an oscillation output having a frequency that is variable; and a control circuit including a frequency/phase comparator, a first control signal generation circuit and a second control signal generation circuit; wherein said frequency/phase comparator receives a reference clock signal and said oscillation output and outputs a difference signal to said first and second control signal generation circuit; wherein said first control signal generation circuit produces a first control signal for controlling the threshold voltage of said MIS transistors of said logic circuit in accordance with said difference signal; wherein said second control signal generation circuit produces a second control signal for controlling the threshold voltage of said MIS transistors of said oscillation circuit in accordance with said difference signal; and wherein said each of first and second control signal generation circuit produces each of said first and second control signal so that said difference signal is controlled to become smaller.