A Compression Improvement Technique for Low-Power Scan Test Data

The huge test data volume, test time and power consumption are major problems in system-on-a-chip testing. To tackle those problems, we propose a new test data compression technique. Initially, don't-cares in a pre-computed test cube set are assigned to reduce the test power consumption, and then, the fully specified low-power test data is transformed to improve compression efficiency by neighboring bitwise exclusive-or (NB-XOR) scheme. Finally, the transformed test set is compressed to reduce both the test equipment storage requirements and test application time