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. 27, 2004
Filed:
Oct. 21, 2002
Isaac Kantorovich, Chestnut Hill, MA (US);
Christopher Lee Houghton, Westborough, MA (US);
James J. St. Laurent, Oakham, MA (US);
Hewlett-Packard Development Company, L.P., Houston, TX (US);
Abstract
A method of measuring impedance in a system comprises holding a microprocessor in reset mode and providing a clock to the microprocessor at a frequency FCLK while measuring a first current level, providing the clock at frequency FCLK/N while measuring a second current level, where N is a positive integer, measuring the voltage at a plurality of ports in the system a plurality of times to obtain a plurality of sets of voltage measurements while holding the microprocessor in reset mode, toggling the clock frequency between FOLK and FOLK/N, and generating a periodic current waveform. The voltage measurements are averaged. The method further comprises determining and removing clock frequency-dependent noises to generate a filtered average voltage, and determining an impedance by dividing a Fourier component of the filtered average voltage by a Fourier component of the periodic current waveform having alternating first and second current levels.