Patent · US Expired

Electrically programmable memory with improved retention of data and a method of writing data in said memory

US5652720A · kind A · utility

61Cited by
11References
49Claims
0Family size

Assignee

Inventors

Key dates

Filing dateDec 18, 1995
Grant dateJul 29, 1997
Priority date
Expiry dateDec 18, 2015

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG11C16/3418
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

The present invention concerns an electrically programmable memory and a method for writing within this memory. In order to avoid the degradation of information in a memory cell following a number of write cycles in the other cells of the same row, the present invention includes a sequence to be carried out before each write cycle of a word within a row. A systematic reading of all the words of a row by using three different read reference potentials is performed in order to find a cell that gives non-compatibility results between any two of the three read cycles. The words of the row are stored in a register. If a non-compatible result is found, which indicates a degradation of information in the row, a systematic re-write of all the words of the row is carried out.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.