Importance

Loading Importance Indicators...

Abstract

An IC is divided into four circuit blocks. These four circuit blocks have the same function. While one of the circuit blocks is not functioning, a mode setting circuit generates mode control signals for selecting a mode in which the operation frequency of the circuit block is set lower than in a normal operation mode. A main control circuit controls the entire operation of the IC, and generates clock signals for defining the operations of the circuit blocks. Sub-control circuits are arranged so as to correspond to the circuit blocks and receive their respective mode control signals and clock signals. Upon receiving the mode control signals, the sub-control circuits controls their corresponding circuit blocks as to whether the circuit blocks are operated in the normal operation mode or at a frequency lower than that in the normal operation mode. In the normal operation mode, the sub-control circuits each set the amount of direct current of a direct current supply circuit arranged in its corresponding circuit block to a normal value, in response to the mode control signals. In the special operation mode, the sub-control circuits each make the amount of direct current smaller than in the normal operation mode.

Loading the Abstract Image...

First Claim