Low Power Test Compression with Programmable Broadcast-Based Control

This paper introduces a low-power test compression scheme that can also be used in a conventional BIST environment. The key contribution is an observation that simple broadcasting of a constant value to predetermined subsets of scan chains allows visible reductions of both toggling rates and pattern counts provided these subsets can be regrouped when feeding scan chains with either decompressed test patterns or pseudorandom vectors. While the proposed solution requires minimal modifications of the existing scan gating logic, its synergistic use with test compression algorithms yields a low scan load switching activity, reduced test time, and less intensive traffic of control data. Consequently, the proposed scheme helps to resolve problems related to test power dissipation and elevated test durations.