The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 10, 2014
Filed:
Aug. 08, 2012
Haruka Obata, Tokyo, JP;
Tatsuyuki Ishikawa, Kanagawa, JP;
Hironori Uchikawa, Kanagawa, JP;
Kenji Sakurada, Kanagawa, JP;
Haruka Obata, Tokyo, JP;
Tatsuyuki Ishikawa, Kanagawa, JP;
Hironori Uchikawa, Kanagawa, JP;
Kenji Sakurada, Kanagawa, JP;
Kabushiki Kaisha Toshiba, Tokyo, JP;
Abstract
A semiconductor memory device includes a semiconductor memory unit which stores LDPC encoded data, and a decoding unit which decodes the encoded data, wherein the decoding unit performs serial decoding using the posterior likelihood ratio as it is for a column element likelihood ratio when the absolute value of the posterior likelihood ratio is not smaller than a threshold and using the column element likelihood ratio as it is for the posterior likelihood ratio when the absolute value of the column element likelihood ratio is not smaller than the threshold, and if the decoding does not succeed even after a predetermined first cycle count of iterative processing is performed or if the number of syndrome errors becomes smaller than a predetermined first syndrome error count, the decoding unit shrinks the absolute values of at least some of posterior likelihood ratios and resets all prior likelihood ratios to '0.'