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. 09, 1991
Filed:
Feb. 13, 1990
Darius F Tanksalvala, Denver, CO (US);
Douglas A Quarnstrom, Fort Collins, CO (US);
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
Circuit points in an integrated circuit (IC) are monitored at pads normally used to carry information between ports of a normal source on the IC (such as input/output points of a cache control), and a memory unit off the IC. The pads are time-shared between their normal and monitoring functions. Each pad is shared by a port of the normal source (the cache control) and a pair of alternative sources to be monitored. During times when the alternative sources are accessed through a pad, they are connected to it alternately, so that, on a first level, each pad is shared between a normal source and a pair of alternative sources, and, on a second level, each such pad is shared between the two alternative sources when they are being accessed.