{
  "slug": "error-syndrome",
  "term": "Error syndrome",
  "aliases": [
    "Syndrome (error-correcting codes)",
    "ECC syndrome"
  ],
  "definition": "An error syndrome is the result of applying a linear code's parity-check equations to a received word.",
  "note": "With parity-check matrix H and received word r, the syndrome is H r^T over the code's field. Zero indicates code membership, not identity with the originally stored word; different error patterns can share a syndrome. [tilborg-coding]\n\nLinux v6.12 bch_decode can accept precomputed syndromes and returns located-error counts or error codes. It does not correct the input buffer itself. Located errors may be in payload or ECC: only locations below 8 * len select payload bits to flip. A returned count is not an unconditional physical error count relative to the original word. [linux-bch-v612]",
  "related": [
    "error-correcting-code",
    "codeword",
    "bch-code",
    "hamming-distance",
    "ldpc"
  ],
  "citations": [
    {
      "id": "tilborg-coding",
      "title": "H. C. A. van Tilborg: Coding Theory, a First Course, sections 2.1-2.2 and 4.2",
      "url": "https://henkvt.win.tue.nl/images/CODING.pdf",
      "accessed": "2026-10-25"
    },
    {
      "id": "linux-bch-v612",
      "title": "Linux v6.12 lib/bch.c: bch_decode return values, caller correction and syndrome processing",
      "url": "https://github.com/torvalds/linux/blob/v6.12/lib/bch.c#L915-L1015",
      "accessed": "2026-10-25"
    },
    {
      "id": "hesela-bch",
      "title": "Hesela: BCH, LDPC and the RBER aggregation trap, decoder contracts",
      "url": "https://hesela.com/analyses/nand-ecc-bch-vs-ldpc/#decoder-contract",
      "accessed": "2026-10-25"
    }
  ],
  "status": "shipping",
  "advantages": [],
  "limitations": [],
  "supersedes": [],
  "supersededBy": [],
  "firstSeen": null,
  "lastSeen": null,
  "updated": "2026-10-25"
}