System for updating error map of fault tolerant memory.

摘要

An online system (6) is disclosed for mapping errors into an error map (64) as read data is transferred between a relatively large fault tolerant semiconductor memory system (5) and a CPU without interfering with the normal use of the memory. The error mapping system permits a fault alignment exclusion mechanism to develop permute vectors which realign pair faults that were located at the same memory address. Having an up-to-date fault map which reflects the current error status of the memory when it is online and which reflects errors based on user data patterns greatly enhances the memory system and facilitates fault alignment exclusion efficiency.