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:
Apr. 16, 1991
Filed:
Oct. 28, 1988
Scott Markinson, Goffstown, NH (US);
Michael Schuster, Norwood, MA (US);
Thomas Hogan, Worcester, MA (US);
Apollo Computer, Inc., Chelmsford, MA (US);
Abstract
A clock generation circuit on each circuit board of a computer system and which removes board-to-board system skew in clock signal distribution. A phase-locked loop is employed to maintain synchronization between the system reference clock signal distributed to each board and the outputs of the distribution gate array in the generation circuit on each board. A 2X frequency clock is provided by combining the clock signal with a delayed version of itself. A second order loop is employed to monitor the duty cycle of the 2X frequency clock and to adjust the duty cycle of the regular frequency clock to provide cycle-to-cycle symmetry for the 2X frequency clock.