Patent · US Active

Spare block management of non-volatile memories

US8040744B2 · kind B2 · utility

119Cited by
86References
48Claims
0Family size

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Key dates

Filing dateJan 5, 2009
Grant dateOct 18, 2011
Priority date
Expiry dateAug 21, 2029

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG11C2211/5641
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

Techniques for the management of spare blocks in re-programmable non-volatile memory system, such as a flash EEPROM system, are presented. In one set of techniques, for a memory partitioned into two sections (for example a binary section and a multi-state section), where blocks of one section are more prone to error, spare blocks can be transferred from the more error prone partition to the less error prone partition. In another set of techniques for a memory partitioned into two sections, blocks which fail in the more error prone partition are transferred to serve as spare blocks in the other partition. In a complementary set of techniques, a 1-bit time stamp is maintained for free blocks to determine whether the block has been written recently. Other techniques allow for spare blocks to be managed by way of a logical to physical conversion table by assigning them logical addresses that exceed the logical address space of which a host is aware.

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