Bit-symbol recognition method and structure for multiple-bit storage in non-volatile memories

摘要

Storage of information represented by a multi-bit word in a single non-volatile memory cell is made possible by programming the threshold voltage of the non-volatile memory to a specific threshold level corresponding to the multi-bit word. Stored or generated multi-bit words are scanned and converted into a gate voltage to be applied to the non-volatile memory cell until the electrical response from the non-volatile memory cell indicates that the voltage generated from the specific multi-bit word which has been applied to the gate matches the information stored in the non-volatile memory cell. The matched multi-bit word is read out of storage and represents the stored bits in the single non-volatile memory cell.