Read only memory cell for storing two bits of data, has one terminal connected to ground voltage line and selection signal lines, or not connected to any of signal lines, and cell storing two bits of data based on connection

摘要

The cell has a pair of terminals, with respective terminal connected to word line and bit line. A third terminal is connected to a ground voltage line and a pair of selection signal line, or not connected to any signal lines. The cell stores two bits of data according to the connection of the third terminal. The word line is selected by a row address, and the bit and the selection lines are selected by a column address. Independent claims are also included for the following: (a) a method for programming a read only memory (ROM) cell (b) a method of forming a layout of a ROM cell (c) a ROM device including a Read only memory cell.