摘要 |
<p>Error correction and error detection related to DRAM chip failures, particularly adapted server memory subsystems. It uses x4 bit DRAM devices organized in a code word of 128 data bit words and 16 check bits (Fig 5, 54 ). These 16 check bits (Fig 5, 54) are generated in such a way as to provide a code capable of 4 bit adjacent error correction within a family (i.e., in a x4 DRAM) and double bit non-adjacent error detection across the entire 128 bit word, with single bit correction across the word as well. Each device can be thought of as a separate family of bits, errors occurring in more than one family are not correctable, but may be detected if only one bit in each of two families is in error. Syndrome generation and regeneration are used together with a specific large code word. Decoding the syndrome and checking it against the regenerated syndrome yield data sufficient for providing the features described.</p> |