US Patent 7940579 Semiconductor integrated circuit device

A semiconductor integrated circuit device includes: a memory cell array composed of electrically rewritable memory cells; an internal voltage generating circuit having a boosting circuit for generating a voltage boosted from a supply voltage, and a voltage detecting circuit for detecting an output voltage of the boosting circuit as a monitor voltage and controlling on/off of the boosting circuit for holding the output voltage of the boosting circuit at a specified level, the internal voltage generating circuit outputting the output voltage of the boosting circuit as an internal voltage; a control circuit for controlling the internal voltage generating circuit; and a writing circuit for applying the internal voltage to the memory cell as a writing voltage when writing data into the memory cell, wherein the control circuit controls the internal voltage to a first voltage necessary for writing data into the memory cell when writing data into the memory cell, and to a second voltage lower than the first voltage in a write verify operation following the data write operation.