{
  "patent_number": "US 12450117",
  "country": "US",
  "title": "How a Special Memory Chip Helps Fix Broken 3D NAND Storage",
  "original_title": "Firmware repair for three-dimensional NAND memory",
  "summary": "This patent describes a special content addressable memory (CAM) system that quickly finds and reroutes around defective memory locations in 3D NAND storage using multiple processing units at once.",
  "what_it_does": "The patent describes a Content Addressable Memory (CAM) system designed to repair memory, specifically 3D NAND. It includes a \"CAM register\" that stores a \"mapping table\" (Claim 1). This table holds \"first addresses\" (defective locations, Claim 8) and \"second addresses\" (redundant, working locations, Claim 9). The system has \"N comparators\" that check \"N input signals\" from \"N microcontroller units\" against the \"first addresses\" in the table (Claim 1). If a comparator finds a match (meaning a requested address is defective), it sends an \"output enablement signal\" (Claim 2, 4) to one of \"N multiplexers\". These multiplexers then use the mapping table to output a \"second address\" (the redundant, working location) instead of the defective one (Claim 1, 3). For example, if a microcontroller unit tries to read data from a memory page marked as defective, the CAM quickly identifies it and redirects the read operation to a spare, working page.",
  "what_it_does_not_cover": [
    "CAM systems that do not use N comparators and N multiplexers working in parallel with N microcontroller units (Claim 1).",
    "Memory repair systems that do not rely on a mapping table of first (defective) and second (redundant) addresses (Claim 1, 8, 9).",
    "CAMs used for general data lookup or caching without the specific purpose of identifying and remapping defective memory locations (Claim 6, 8, 9).",
    "Memory devices that are not 3D NAND memory, as implied by the patent's context and Claim 10.",
    "Repair mechanisms that don't involve comparing input addresses to a stored list of defective addresses."
  ],
  "filed": "2023-12-04",
  "granted": "2025-10-21",
  "expires": "2043-12-04",
  "status": "active",
  "holder": "Yangtze Memory Technologies Co",
  "holder_url": "https://patentbrief.org/company/yangtze-memory-technologies-co",
  "inventors": [
    {
      "name": "Yanlan Liu",
      "url": "https://patentbrief.org/inventor/yanlan-liu"
    }
  ],
  "times_cited": 0,
  "tags": [
    "semiconductors",
    "consumer_electronics",
    "telecommunications",
    "software",
    "data_storage"
  ],
  "abstract": "The present disclosure provides a content addressable memory (CAM). The CAM includes a CAM register configured to store a mapping table, N comparators coupling to the CAM register, and N multiplexers coupling to the N comparators respectively and to the CAM register. The mapping table includes first addresses and second addresses. Each one of the first addresses corresponds to one of the second addresses. Each of the N comparators is configured to compare the first addresses with one of N input signals, where N is an integer greater than 1. The N input signals come from N microcontroller units. The N multiplexers is configured to generate N output signals. At least one of the N output signals is obtained according to the mapping table and a comparison output by one comparator of the N comparators.",
  "url": "https://patentbrief.org/patent/us/12450117/firmware-repair-for-three-dimensional-nand-memory",
  "markdown_url": "https://patentbrief.org/patent/us/12450117/firmware-repair-for-three-dimensional-nand-memory/md",
  "google_patents_url": "https://patents.google.com/patent/US12450117",
  "relatedPatents": [
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  ]
}