Two-Way Multicasting for Test Data Compression

This paper presents a two-way multicasting scan (TMS) architecture for test data compression. TMS records the difference address between neighboring broadcasts using less control bits to achieve two-directional cascaded broadcastings. Analyses on test pattern compatibility are made to determine the scan chain order so as to minimize the total number of broadcasts. In addition, the volume of sub-pattern data which is sent into scan chains in a broadcast is largely reduced by the partial data reuse method. Experimental results show that with smaller hardware overhead TMS achieves a better compression effect than similar work conducting multicast scan.