Integrated circuit storage device

Abstract

Abstract PURPOSE:To increase the versatility of an integrated circuit, by changing the threshold value of an MOSFET having a floating gate for a storage device with a substrate voltage and using RAM and ROM functions separately. CONSTITUTION:The drain of an MOSFET1 having a floating gate is connected to a data line 7, the source is connected to an information storage capacitor 5 and the gate is to a word line 3 respectively, and the threshold value is changed with a substrate voltage VBG. Because of two threshold voltages to be given, an ROM function is obtained for the write-in of ROM. Further, the write-in for the RAM is made by making the voltage VBG as 0 volt, and the line 6 as 0 volt, respectively, and when the line 6 is made to a high potential through the application of write-in data high level or 0 volt to the line 7 and returned to 0 volt, write-in for the RAM is made. This is similar to the readout, and functions of RAM and ROM are separately used to increase the versatility of an integrated circuit storage device.

Inventors

• 👤 Tomoharu Nakamura
• 👤 Akira Kato

Bibliographic Details