Invention Grant
- Patent Title: At-rate SERDES clock data recovery with controllable offset
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Application No.: US15000028Application Date: 2016-01-18
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Publication No.: US09813227B2Publication Date: 2017-11-07
- Inventor: Jianghui Su
- Applicant: Oracle International Corporation
- Applicant Address: US CA Redwood City
- Assignee: ORACLE INTERNATIONAL CORPORATION
- Current Assignee: ORACLE INTERNATIONAL CORPORATION
- Current Assignee Address: US CA Redwood City
- Agency: Marsh Fischmann & Breyfogle LLP
- Agent Daniel J. Sherwinter
- Main IPC: H04L7/00
- IPC: H04L7/00 ; H04L7/02 ; H04L7/033

Abstract:
Embodiments include systems and methods for applying a controllable early/late offset to an at-rate clock data recovery (CDR) system. Some embodiments operate in context of a CDR circuit of a serializer/deserializer (SERDES). For example, slope asymmetry around the first precursor of the channel pulse response for the SERDES can tend to skew at-rate CDR determinations of whether to advance or retard clocking. Accordingly, embodiments use asymmetric voting thresholds for generating each of the advance and retard signals in an attempt to de-skew the voting results and effectively tune the CDR to a position either earlier or later than the first precursor zero crossing (i.e., h(−1)=0) position. This can improve link margin and data recovery, particularly for long data channels and/or at higher data rates.
Public/Granted literature
- US20160241383A1 AT-RATE SERDES CLOCK DATA RECOVERY WITH CONTROLLABLE OFFSET Public/Granted day:2016-08-18
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