Patent ID: 7071768
Filing Date: 2006-07-04
Classification: G11C

Abstract:
1. A semiconductor integrated circuit comprising: an internal supply voltage generation circuit which generates an internal supply voltage by decreasing an external supply voltage; a supply voltage monitoring circuit which monitors a level of the internal supply voltage; a clock control circuit which generates an internal clock having a frequency controlled in accordance with an operation speed of an internal circuit and provides the generated internal clock to the internal circuit; and a voltage control circuit which controls the level of the internal supply voltage generated by the internal supply voltage generation circuit to become a level corresponding to the frequency of the internal clock, wherein, the clock control circuit increases the frequency of the internal clock to a first frequency from a second frequency lower than the first frequency, after the supply voltage monitoring circuit detects the level of the internal supply voltage is increased to a level corresponding to the first frequency, and wherein the supply voltage monitoring circuit outputs an internal reset signal when the level monitored by the supply voltage monitoring circuit becomes lower than a predetermined minimum level, so that data in a register or a memory in the internal circuit is saved in response to the internal reset signal.