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:
Jul. 21, 2009
Filed:
Apr. 30, 2004
Applicants:
John D. Logue, Placerville, CA (US);
Alvin Y. Ching, San Jose, CA (US);
Wei Guang LU, San Jose, CA (US);
Inventors:
John D. Logue, Placerville, CA (US);
Alvin Y. Ching, San Jose, CA (US);
Wei Guang Lu, San Jose, CA (US);
Assignee:
XILINX, Inc., San Jose, CA (US);
Attorneys:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H03L 7/06 (2006.01); H03H 11/16 (2006.01);
U.S. Cl.
CPC ...
Abstract
An automatic calibration scheme is provided, which calibrates the equivalent taps per period ETT/P every time a delay lock loop is used. More specifically, a digital phase shifter is used to measure equivalent taps per period ETT/P. Alternately, the digital phase shifter is used to directly measure the signal delay through a clock phase shifter of the delay lock loop, thereby directly determining the high frequency and low frequency overhead constants.