Patent · US Expired

Memory circuit having parity cell array

US7032142B2 · kind B2 · utility

26Cited by
4References
18Claims
0Family size

Assignee

Inventors

Key dates

Filing dateOct 17, 2002
Grant dateApr 18, 2006
Priority date
Expiry dateDec 27, 2023

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG11C2211/4062
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

A memory circuit has: a real cell array; a parity generating circuit for generating a parity bit from data of the real cell array; a parity cell array; a refresh control circuit, which sequentially refreshes the real cell array, and when an internal refresh request and a read request coincide, prioritizes a refresh operation; a data recovery section, which, in accordance with the parity bit read out from the parity cell array, recovers data read out from the real cell array; and an output circuit for outputting data from the real cell array. Further, the memory circuit has a test control circuit, which, at a first test mode, prohibits a refresh operation for the real cell array to output data read out from the real cell array, and, at a second test mode, controls the output circuit so as to output data read out from the parity cell array.

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