Memory system that supports probalistic component-failure correction with partial-component sparing

Abstract

A memory system that facilitates probabilistic error correction for a failed memory component with partial-component sparing. The memory system accesses blocks of data, each block including an array of bits logically organized into R rows and C columns. The C columns include () a row-checkbit column containing row-parity bits for each of the R rows, () an inner-checkbit column containing X=R−S inner checkbits and S spare bits, and () C-2 data-bit columns containing data bits. Each column is stored in a different memory component. When the memory system determines that a memory component has failed, the memory system examines the pattern of errors associated with the failed component to determine if the failure affects a partial component associated with S or fewer bits. If so, the memory system corrects and remaps data bits from the failed partial component to the S spare data bits in the inner-checkbit column.