Mentor Graphics Corporation

Justyna Zawada

Janusz Rajski

Jerzy Tyszer

Nilanjan Mukherjee

Elham K Moghaddam

Jedrzej Solecki

Sylwester Milewski

Various aspects of the disclosed technology relate to using capture-per-cycle test points to reduce test application time. A scan-based testing system includes a plurality of regular scan chains and one or more capture-per-cycle scan chains on which scan cells capture and compact test responses at predetermined observation points per shift clock cycle.

Test application time reduction using capture-per-cycle test points

Various aspects of the disclosed technology relate to conflict-reducing test point insertion techniques. Locations in a circuit design for inserting test points are determined based on internal signal conflicts caused by detecting multiple faults with a single test pattern. Test points are then inserted at the locations. The internal signal conflicts may comprise horizontal conflicts, vertical conflicts, or both. The test points may comprise control points, observation points, or both.

Test point insertion for low test pattern counts

Various aspects of the disclosed technology relate to techniques of using control test points to enhance hardware security. The design-for-security circuitry reuses control test points, a part of design-for-test circuitry. The design-for-security circuitry comprises: identity verification circuitry; scrambler circuitry coupled; and test point circuitry. The test point circuitry comprises scan cells and logic gates The identify verification circuitry outputs an identity verification result to the scrambler circuitry to enable/disable control test points of the test point circuitry through the logic gates, and the scrambler circuitry outputs logic bits for loading the scan cells to activate/inactivate the control test points through the logic gates.

Growing community of inventors

Paczkowo, Poland

Justyna Zawada