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:
Dec. 08, 2009
Filed:
Dec. 05, 2007
Seok-bo Shim, Kyoungki-do, KR;
Seok-Bo Shim, Kyoungki-do, KR;
Hynix Semiconductor, Inc., Gyeonggi-do, KR;
Abstract
A semiconductor memory device includes a phase comparator, a delay chain, a delay controller, a fine delay chain, a delay model, a locking state detector, and a fine delay controller. The phase comparator compares a phase of a reference clock with that of a feedback clock. The delay chain delays and outputs the reference clock. The delay controller controls a delay value of the delay chain in response to the comparison result of the phase comparator. The fine delay chain outputs a delay value of a clock outputted from the delay chain. The delay model delays a clock to a modeled delay value to provide a delayed clock as the feedback clock. The locking state detector generates a locking variation signal corresponding to a phase difference between the reference clock and the feedback clock. The fine delay controller controls a fine adjustment value of the fine delay chain.