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:
Oct. 21, 2003
Filed:
Jul. 13, 2000
Alvar A. Dean, Essex Junction, VT (US);
Joseph A. Iadanza, Hinesburg, VT (US);
David E. Lackey, Jericho, VT (US);
Sebastian T. Ventrone, South Burlington, VT (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A method of testing a digital logic circuit comprises first providing a logic circuit having a plurality of interconnected circuits each having an input and an output; determining a gate level representation of the logic circuit including test nets for determining faults in the circuit; and identifying a portion of the nets which are most difficult to test, including nets which are most difficult to control and nets which are most difficult to observe. The method then includes inserting into the logic circuit control latches for nets which are determined to be most difficult to control and inserting into the logic circuit observation latches for nets which are determined to be most difficult to observe. Using the inserted control latches and observation latches, the method further includes testing the nets which are determined to be most difficult to control and nets which are hardest to observe and determining faults in the circuit. As a result of the method of the present invention, testing is completed in a time faster than if the nets were tested without the control latches and the observation latches. The portion of the nets which are most difficult to test are preferably identified by overall test time impact, and the nets having longest test times are determined to be most difficult to control and most difficult to observe.