PURPOSE: To obtain a voltage reference generating circuit used for ensuring the correct control of a voltage generating circuit for an integrated circuit device.
CONSTITUTION: An external feeding voltage VDD is switched into a band gap reference generator 20 to start the generator with a starter circuit VREFINIT1 by receiving a signal RID existing within the initial power up phase in the device. A BOSC signal from an oscillator excited at the time of power up continuing is also received with a start up circuit. A pump is driven with the oscillator, whereby the VDD reference voltage VDDREF is driven even after the RID became an inactive state. The BOSC signal is suspended at the end of power up. When power up is finished, a PBOSC signal driving the main power VDDREF is obtained. After power up, a feeding voltage VPERI used for an access circuit to a DRAM array is obtained and used as the output to the VDDREF for the purpose of the reference.