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:
Dec. 13, 1988
Filed:
Nov. 18, 1987
Douglas W Raymond, Orinda, CA (US);
Nicholas Winfield, Towcester, GB;
Zehntel, Inc., Walnut Creek, CA (US);
Abstract
A method of detecting possibly electrically-open connections between circuit nodes and pins of components physically connected to the nodes. The pins include input pins and output pins, the input pins connected to corresponding input nodes and the output pins connected to corresponding output nodes. The method comprises the steps of determining if the connections between the input pins and the input nodes can be tested, and then testing for an electrically-open connection between each input pin and its corresponding input node. The two-step method of determining if the connections between the input pins and the input nodes can be tested includes a first step of determining if the output nodes exhibit activity in response to application of stimuli to the input nodes, and continuing testing if there is activity. The second step is determining if each output node exhibits a signature repeated identically in response to stimuli repeated identically at all the input nodes. No attempt is made to test the connections between the input pins and their corresponding input nodes unless all the signatures measured at the output nodes are repeatable. Testing for an electrically-open connection between each input pin and its corresponding input node includes the steps of applying a first stimulus to a selected input node while applying a second stimulus to the rest of the input nodes, and then generating a signal indicating a possibly open connection if for any given output node the response is not identical to the response when the second stimulus is applied to all the input nodes.