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:
Apr. 17, 2012
Filed:
Oct. 05, 2010
Derick Gardner Behrends, Rochester, MN (US);
Todd Alan Christensen, Rochester, MN (US);
Travis Reynold Hebig, Rochester, MN (US);
Daniel Mark Nelson, Rochester, MN (US);
Derick Gardner Behrends, Rochester, MN (US);
Todd Alan Christensen, Rochester, MN (US);
Travis Reynold Hebig, Rochester, MN (US);
Daniel Mark Nelson, Rochester, MN (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A circuit and method increases the repeatability of physically undetectable functions (PUFs) by enhancing the variation of signal delay through two delay chains during chip burn-in. A burn-in circuit holds the inputs of the two delay chains at opposite random values during the burn-in process. All the PFETs in the delay chains with a low value at the input will be burned in with a higher turn on voltage. Since the PFETs affected in the two delay chains are driven by opposite transitions at burn-in, alternating sets of delay components in the two delay chains are affected by the burn-in cycle. Under normal operation, both of the delay chains see the same input so only one chain has an increase in delay to achieve a statistically reliable difference in the two delay paths thereby increasing the overall repeatability of the PUF circuit.