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:
Jun. 14, 1988
Filed:
Feb. 11, 1987
Daniel Wissell, Westford, MA (US);
Digital Equipment Corporation, Maynard, MA (US);
Abstract
Apparatus and method are disclosed for identifying and measuring random contact interruption events in a circuit interconnection device. A comparator circuit, adapted to be operated at high frequencies, identifies when an interrupt event has occurred. The comparator circuit, as a result of the interruption event, causes a high frequency counter circuit to count clock pulses. The count in the counter circuit is continuously applied to an RAM memory circuit, write-enabled at an addressed memory location. After the interruption event is terminated, the RAM memory circuit is no longer write enabled at the addressed location and the addressed location is changed (incremented) in preparation for the next event. The counter circuit is also reset to zero in preparation for the next interruption event. The number of counts from a clock unit having a known frequency provides the duration of the interruption event. With the use of a clock unit operated at 100 MHz, interrupt events from 10 nanoseconds to 9.99 microseconds can be identified. Because of the frequency at which the testing is performed, the input impedance of the comparator circuit must be matched to the impedance of the circuit interconnection device.