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:
Feb. 22, 2011
Filed:
Aug. 24, 2007
Ingemar Holm, Stuttgart, DE;
Ralph C. Koester, Tuebingen, DE;
Cedric Lichtenau, Boeblingen, DE;
Thomas Pflueger, Leinfelden, DE;
Mack W. Riley, Austin, TX (US);
Ingemar Holm, Stuttgart, DE;
Ralph C. Koester, Tuebingen, DE;
Cedric Lichtenau, Boeblingen, DE;
Thomas Pflueger, Leinfelden, DE;
Mack W. Riley, Austin, TX (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A secure Power-on Reset (POR) engine is provided, inside a processor chip, which guarantees a secure initialization of the chip to enable secure code execution. External access to chip resources is limited to a very few targeted settings that do not compromise the chip security. The POR engine comprises a small state machine that runs through a predefined sequence coded in persistent memory contained in the processor chip. The state machine initializes the chip and allows external access from an external processor to only some scan chains of the processor chip in order to configure interfaces, and the like, without compromising the chip security. The state machine also manages the encryption keys that are used to verify that the code, fetched by the processor to complete the initialization in software, is not modified by a third party.