Self-identifying memory errors

Abstract

A memory region can durably self-identify as being faulty when read. Information that would have been assigned to the faulty memory region can be assigned to another of that sized region in memory using a replacement encoding technique. For phase change memory, at least two fault states can be provided for durably self-identifying a faulty memory region; one state at a highest resistance range and the other state at a lowest resistance range. Replacement cells can be used to shift or assign data when a self-identifying memory fault is present. A memory controller and memory module, alone or in combination may manage replacement cell use and facilitate driving a newly discovered faulty cell to a fault state if the faulty cell is not already at the fault state.

Dependencies are inferred from the claim text.