A Multilayer Data Copy Scheme for Low Cost Test with Controlled Scan-In Power for Multiple Scan Chain Designs

The random-like filling strategy pursuing high compression for scan test introduces large test power. To pursue high compression in conjunction with reducing test power for multiple scan chain designs is even harder and very few works were dedicated to solve this problem. This paper proposes and demonstrates a multilayer data copy (MDC) scheme for test compression as well as test power reduction for multiple scan designs. The scheme utilizes a buffer, which supports fast load using previous loaded data, to achieve test data compression and test power reduction at the same time. The scheme can be applied ATPG-independently or to be incorporated in an ATPG to generate highly compressible and power efficient test sets. Experiment results on benchmarks show that test sets generated by the scheme had large compression and power saving with little area design overhead