Decentralized BIST Methodology for System Level Interconnects

This paper presents an architecture for the local generation of global test vectors for interconnects in a multiple scan chain environment. A unified BIST module is inserted as the gateway for each scan chain to transform the hierarchy of backplane, boards, and scan chains into a one-dimensional array of scan chains. The BIST modules are identical for all the scan chains except for the programmable personalized memories. The personalized memory contains a scan stage type table for the test generation, response compression, and driver contention avoidance. It also contains a scan chain identification number which serves as the seed for the generation of globally distinct serial vectors. The proposed methodology achieves 100% coverage on stuck-at and short faults.