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. 26, 2015
Filed:
Aug. 09, 2006
Erik J. Marinissen, Leuven, BE;
Sandeep Kumar Goel, Eindhoven, NL;
Andre K. Nieuwland, Waalre, NL;
Hubertus G. H. Vermuelen, Eindhoven, NL;
Hendrikus P. E. Vranken, Weert, NL;
Erik J. Marinissen, Leuven, BE;
Sandeep Kumar Goel, Eindhoven, NL;
Andre K. Nieuwland, Waalre, NL;
Hubertus G. H. Vermuelen, Eindhoven, NL;
Hendrikus P. E. Vranken, Weert, NL;
NXP B.V., Eindhoven, NL;
Abstract
An integrated circuit () comprises a functional circuit (-) that contain information that must be secured against unauthorized access. The integrated circuit comprises a test access circuit () coupled to the functional circuit (-), and a plurality of fuse elements () coupled to the test access circuit (). The fuse elements () are connected in a circuit configuration that makes the functional circuit (-) consistently accessible via the test access circuit () only when first fuse elements () of the plurality are in a blown state and second fuse elements () of the plurality are in a not-blown state. As a result the integrated circuit can be tested after selectively blowing all of the first fuse elements (). After testing at least part of the second fuse elements () is blown. As a result, a person that does not know which fuse elements are first fuse elements and which are second fuse elements is presented with difficulties to restore the integrated circuit to a state where test access with the danger of access to the secured information is possible.