Method for using XOR trees for physically efficient scan compression and decompression logic

US9513335B1 · kind B1 · utility

Assignee

• Cadence Design Systems, Inc. · US

Inventors

• Steev Wilcox · San Jose, US
• Brian Foutz · Charlottesville, US
• Paul Alexander Cunningham · San Jose, US
• Vivek Chickermane · Ithaca, US
• Krishna Vijaya Chakravadhanula · Vestal, US

Key dates

• Filing date: Jun 12, 2015
• Grant date: Dec 6, 2016
• Expiry date: Jun 12, 2035

Classification

• Technology area (CPC G): Physics
• CPC primary: G01R31/318547
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

Methods and apparatus for decompressing test data using XOR trees for application to scan chains of a design for test (DFT) integrated circuit in a physically efficient construction are disclosed. Moreover, methods and apparatus for compressing test response data from scan chains in a DFT integrated circuit in a physically efficient construction are disclosed. The XOR tree decompression method may comprise splitting signals at each node of the XOR trees according to distribution logic implemented by a set of XOR gates. The XOR tree compression method may comprise combining signals at each node of the XOR trees according to combination logic implemented by a set of XOR gates.