US Patent 7960777 Multi-valued mask ROM

A mask ROM is provided with a plurality of memory cells each including first and second nodes, and a transistor having a source and drain connected to the first and second nodes, respectively. A first memory cell out of the plurality of memory cells further includes a first resistive interconnection which provides an electrical connection between the first and second nodes. The resistance of the first resistive interconnection is adjusted depending on data stored onto the first memory cell.