{"schema_version":"1.0","canonical_url":"https://patentable.app/patents/US-9645177","patent":{"patent_number":"US-9645177","title":"Retention-drift-history-based non-volatile memory read threshold optimization","assignee":null,"inventors":[],"filing_date":"2014-01-31T00:00:00.000Z","publication_date":"2017-05-09T00:00:00.000Z","cpc_codes":["G11C","G11C","G11C","G11C","G11C","G11C","G11C","G11C","G11C","G11C"],"num_claims":34,"abstract":"An SSD controller dynamically adjusts read thresholds in an NVM to reduce errors due to device threshold voltage distribution shifts, thus improving performance, reliability, and/or cost of a storage sub-system, such as an SSD. A retention drift clock uses one or more reference pages (or ECC units or blocks) on one or more NVM die as read threshold over time/temperature references, and uses a function of those values as a measure of drift (over time/temperature). At some initial time, the one or more reference pages are programmed and an initial read threshold is measured for each of the one or more reference pages. In some embodiments, read threshold values are averaged among one or more of: all references pages on the same die; and all reference pages in the same one or more die in an I/O device."},"analysis":{"summary":null,"layman_explanation":null,"technical_analysis":null,"business_analysis":null,"faqs":null,"topics":[],"tech_cluster":null},"seo":{"title":"Retention-drift-history-based non-volatile memory read threshold optimization","description":"An SSD controller dynamically adjusts read thresholds in an NVM to reduce errors due to device threshold voltage distribution shifts, thus improving performance, reliability, and/or cost of a storage ","keywords":[]},"attribution":{"source":"Patentable","source_url":"https://patentable.app","canonical_url":"https://patentable.app/patents/US-9645177","license":"CC-BY-4.0-like","license_terms":"AI-generated analysis on this page (summary, layman_explanation, technical_analysis, business_analysis, faqs) may be reused with attribution and a visible link back to the canonical URL above. Patent abstracts, claims, and bibliographic data are USPTO public domain.","required_link":"https://patentable.app/patents/US-9645177","citation_suggestion":"Patentable. \"Retention-drift-history-based non-volatile memory read threshold optimization\" (US-9645177). https://patentable.app/patents/US-9645177","copyright_holder":"Nomic Interactive Technology LLC"},"links":{"html":"https://patentable.app/patents/US-9645177","json":"https://patentable.app/api/llm-context/US-9645177","site":"https://patentable.app","llms_txt":"https://patentable.app/llms.txt"},"generated_at":"2026-06-06T05:38:22.467Z"}