Patent ID: 6166577
Filing Date: 2000-12-26
Classification: H03K

Abstract:
A microcomputer comprising:a main circuit comprising MIS transistors formed on a single semiconductor substrate which implements a certain logical processing;an oscillation circuit comprising MIS transistors formed on said single semiconductor substrate which effectively monitors delay characteristics of said main circuit and produces an oscillation output having a frequency that is variable;an operation clock signal supply circuit which receives a mode signal and a clock signal, and produces an operation clock signal having a frequency determined by said mode signal;a control circuit which receives said operation clock signal and said oscillation output find produces a control signal for controlling a threshold voltage of the MIS transistors of said main circuit and a threshold voltage of MIS transistors of said oscillation circuit such that the frequency of said oscillation output corresponds to the frequency of said operation clock signal; anda load detecting means which detects a load of said main circuit and outputs said mode signal, corresponding to an operation mode of said microcomputer, to said operation clock signal supply circuit,whereby the operation mode determines whether the microcomputer should run with higher speed performance at higher power consumption or wish lower speed performance at lower power consumption.