Test pattern generation and clock disabling for simultaneous test time and power reduction

Scan-based design has been widely used to transport test patterns in a system-on-a-chip (SOC) test architecture. Two problems that are becoming quite critical for scan-based testing are long test application time and high test power consumption. Previously, many efficient methods have been developed to address these two problems separately. In this paper, we propose a novel method called the multiple clock disabling (MCD) technique to reduce test application time and test power dissipation simultaneously. Our method is made possible by cleverly modifying and integrating a number of existing techniques to generate a special set of test patterns that is suitable for a scan architecture based on the MCD technique. Experimental results for the International Symposium on Circuits and Systems (ISCAS) ´85 and ´89 benchmark circuits show that significant reduction on both test application time and power dissipation can be achieved compared to the conventional scan method.