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:
May. 10, 2011
Filed:
Oct. 12, 2006
Tom Waayers, Sint Michielsgestel, NL;
Tom Waayers, Sint Michielsgestel, NL;
NXP B.V., Eindhoven, NL;
Abstract
A method and apparatus for testing an integrated circuit core or circuitry external to an integrated circuit core using a testing circuit passes a test vector from a parallel input of the testing circuit along a shift register circuit. The shift register circuit is configured to bypass one or more cores not being tested and to provide the test vector to a core scan chain of the core being tested. The bypassed cores are configured such that the associated shift register circuit portion is driven to a hold mode in which storage elements of the shift register circuit portion have their outputs coupled to their inputs. This method provides holding of the shift register stages when a core is bypassed and in a test mode, and this means the shift register stages are less prone to errors resulting from changes in clock signals applied to the shift register stages.