Patent Number: 6,674,385

Title: Analog-to-digital conversion method and device, in high-density multilevel non-volatile memory devices

Abstract: An analog-to-digital conversion method and device for a multilevel non-volatile memory device that includes a multilevel memory cell. The method comprises a first step of converting the most significant bits contained in the memory cell, followed by a second step of converting the least significant bits. The first step is completed within a time interval corresponding to the rise transient of the gate voltage, and the second step is initiated at the end of the transient. Also disclosed is a scheme for error control coding in multilevel Flash memories. The n bits stored in a single memory cell are organized in different "bit-layers", which are independent from one another. Error correction is carried out separately for each bit-layer. The correction of any failure in a single memory cell is achieved by using a simple error control code providing single-bit correction, regardless of the number of bits stored in a single cell.

Inventors: Micheloni; Rino (Turate, IT), Khouri; Osama (Milan, IT), Pierin; Andrea (Graffignana, IT), Gregori; Stefano (Torre d'Isola, IT), Torelli; Guido (S. Alessio Con Vialone, IT)

Assignee: STMicroelectronics S.r.l.

International Classification: G11C 11/56 (20060101); H03M 1/14 (20060101); H03M 1/36 (20060101); H03M 001/12 ()

Expiration Date: 01/06/2021