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:
Aug. 21, 1990
Filed:
Jul. 08, 1988
Aldo Mastrocola, Everett, MA (US);
Mark Swanson, Arlington, MA (US);
GenRad, Inc., Concord, MA (US);
Abstract
A technique for automatically diagnosing the failure of electronic devices connected to share a common bus. All bus devices are first disabled, and the bus is examined to determine if a failed device is interfering with normal operation by causing the bus to be stuck at a logic high or a logic low level. If the bus is stuck low or high, a forcing voltage nearly equal to either V.sub.ol or V.sub.oh, respectively, is applied to the bus, with all devices still disabled. A disabled bus current is then measured. One at a time, the bus devices are enabled, and the current on the bus measured to determine an enabled bus current. If, for a particular device, the enabled bus current exceeds the disabled bus current by a predetermined amount depending on the drive current specification of the device, it is concluded that the particular device is operating properly.