PURPOSE: To store an optional number of necessary code signals, and set the number of codes optionally by providing a common data line with a storage circuit through switch MOSFET.
CONSTITUTION: Data lines D1WDn are connected to the common data line CD through column selection switches MOSFETs Q7WQ9. Then, the output terminal of a data input buffer DIB for writing which receives a write signal inputted from an external terminal I/O is connected to this common data line CD. When information is read out of a memory cell, the bias voltage is supplied through MOSFETQ13 to the memory cell selected by address decoders X-DCR and Y- DCR. The selected memory cell has a higher or lower threshold voltage than a word line selection level according to written information.
MATSUNO YOUICHI
HARADA KENICHI
HITACHI MICROCUMPUTER ENG