Semiconductor integrated circuit and electronic information device

A semiconductor integrated circuit comprising a plurality of internal circuits, and having a normal operation mode, in which a major core circuit among the plurality of internal circuits performs an operation based on a system clock, and a stand-by mode, in which an operating voltage of the core circuit is decreased to a stand-by voltage that is lower than the operating voltage in the normal operation mode, the semiconductor integrated circuit further comprising:

• a mode switching circuit for switching an operation mode of the core circuit between the normal operation mode and the stand-by mode;
• and
• a stand-by canceling circuit for instructing the mode switching circuit to cancel the stand-by mode,
• wherein:
• the mode switching circuit and the stand-by canceling circuit are configured to operate in asynchronism with the system clock with the stand-by voltage;
• and
• in the stand-by mode, the operating voltage of the core circuit is decreased to the stand-by voltage which is less than the limit of the operation based on the system clock.