Patent ID: 6601003
Filing Date: 2003-07-29
Classification: G01R

Abstract:
A low power-supply voltage detection circuit for detecting drops in power-supply voltage that is supplied to a nonvolatile memory that performs at least one of data writing and page erasing when a memory control signal is active, comprising:a reference voltage generation means for generating and outputting a fixed voltage as a reference voltage; a power supply voltage-dividing means for dividing the voltage between the power-supply voltage and a ground voltage and outputting the result as a voltage-divided voltage; a comparison means for comparing said voltage-divided voltage with said reference voltage, said comparison means outputting a low power-supply voltage signal when said voltage-divided voltage is higher than said reference voltage corresponding to an OFF state, and outputting the low power-supply voltage signal when said voltage-divided voltage is lower than said reference voltage corresponding to an ON state; and a low power-supply voltage control means for effecting control to either execute or suspend for a prescribed time period a memory control signal switching operation in which said memory control signal is activated and output when the low power-supply voltage signal is in the OFF state and said memory control signal is switched from active to inactive when the low power-supply voltage signal changes from the OFF state to the ON state.