Office of Technology Transfer – University of Michigan

Field-Repairable Control Logic

Technology #3510

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Todd M. Austin
Managed By
Joohee Kim
Licensing Specialist, Physical Sciences & Engineering 734-764-8202
Patent Protection
US Patent Pending


Microprocessor design houses perform extensive validation of their designs before production and release to the marketplace. The success of this process may be important to the survival of the company, as the financial impact of microprocessor bugs can be devastating. Designers address correctness concerns through verification, the process of extensively validating all the functionalities of a design throughout the development cycle. Simulation-based techniques are central to this process: they exercise a design with relevant test sequences in the attempt to expose latent bugs. This approach is used extensively in the industry, yet it suffers from a number of drawbacks.


University of Michigan researchers have developed a novel hardware patching mechanism that can detect design errors which escaped the verification process, and can correct them directly in the field. This is achieved through a simple field-programmable state matcher, which can identify erroneous configurations in the processor’s control state and switch the processor into formally verified degraded performance mode, once the a match happens.

Applications and Advantages


  • Microprocessor design and verification


  • Detect and correct infrequently-occurring-nl-errors with almost no performance impact
  • Accurate detection of bug states
  • Low overhead cost