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:
Jan. 02, 2007
Filed:
Jun. 20, 2003
Method and apparatus to construct a fifty percent (50%) duty cycle clock signal across power domains
Hon-mo Raymond Law, Beaverton, OR (US);
Rachael J. Parker, Forest Grove, OR (US);
Hon-Mo Raymond Law, Beaverton, OR (US);
Rachael J. Parker, Forest Grove, OR (US);
Intel Corporation, Santa Clara, CA (US);
Abstract
Some microprocessors are designed such that the microprocessor core clock has a duty cycle of approximately fifty percent. When a clock signal propagates across power domains the clock signal pulse shape will change. The rising edges and falling edges of the clock signal will become asymmetrical (e.g., the duty cycle is no longer fifty percent). According to embodiments of the present invention, a parallel divide function is applied to a clock signal having a frequency f and its complement. The resulting four signals (i.e., f/2, its complement, f/2 at ninety degrees out of phase from f/2 and its complement) are applied to an XOR gate that combines them to generate a clock signal that has a duty cycle of approximately fifty percent and a frequency f, which is the same as the input clock signal.