Memory incorporating error detection and correction

Abstract

A memory in which each word location for a user word not only contains the bit locations for the actual data but also one parity bit for the parity over the entire word location and one correction bit. A fixed number of word locations are grouped to form a memory location for the storage of a memory word. When a word location is read by a data user, the parity bit indicates whether the word location contains none or one bit error. If the user word contains an error, the other word locations of the same memory location and also the associated correction bits are read to correct one arbitrary bit error in the memory word. In given cases, a plurality of bit errors can be corrected if they are situated in bit positions of the same rank within the word locations for the user words. The chance that a multiple error has exactly this configuration can be enhanced by a suitable arrangement of the bit locations in a memory. Thus, a limited amount of redundancy suffices in many cases. Memory words in different memory banks may have correction bits in common.