PURPOSE: To prevent erroneous operation due to noise entered through an input pin in a memory where a current consumption is lowered by decreasing the power supply voltage during standby (data retaining state).
CONSTITUTION: A signal transmission gate is interlaid between an input pin and an input buffer, means for detecting the drop in internal power supply voltage is provided, and the gate is turned off during drop in power supply voltage, thereby inhibiting the transmission of signals from the input pin to the input buffer. By doing this, even though the logic threshold voltage of the input buffer is dropped as a result of a decrease in the internal power supply voltage, the gate interlaid between the input pin and the input buffer is turned off, and noise entered into the input pin cannot be transmitted to the input buffer so that erroneous operation of the circuit can be prevented.
KAJITANI KAZUHIKO
YAMAZAKI TAKASHI
