Invention Grant
- Patent Title: Soft-decision compensation for flash channel variation
- Patent Title (中): 闪光通道变化的软判决补偿
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Application No.: US14507126Application Date: 2014-10-06
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Publication No.: US09483347B2Publication Date: 2016-11-01
- Inventor: Yunxiang Wu , Earl T. Cohen
- Applicant: SEAGATE TECHNOLOGY LLC
- Applicant Address: US CA Cupertino
- Assignee: Seagate Technology LLC
- Current Assignee: Seagate Technology LLC
- Current Assignee Address: US CA Cupertino
- Agency: Smith Tempel Blaha LLC
- Main IPC: H03M13/00
- IPC: H03M13/00 ; G06F11/10 ; G11C29/52

Abstract:
In an SSD controller reading from flash memory, subsequent to failure of an initial soft-decision decoding attempt based on a nominal LLR, soft-decision re-decoding attempts are made using compensated LLR soft-decision information sets, pre-calculated at respective read-equilibrium points corresponding to mean shifts and variance change in the actual charge-state distributions of the flash memory channel. According to embodiment, soft-decision re-decoding attempts are performed without a retry read, or overlapped with one or more retry reads. By overlapping re-decoding with one or more retry reads, the probability of successful decoding increases, the need for further retry reads diminishes, and throughput is improved. The LLR compensation becomes very effective over a large number of retry reads, improving decoding reliability and achieving close to optimal bit error rates, even in the presence of large channel variation.
Public/Granted literature
- US20150169402A1 SOFT-DECISION COMPENSATION FOR FLASH CHANNEL VARIATION Public/Granted day:2015-06-18
Information query
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