Testing system-on-chip by summations of cores' test output voltages

The rapid growing trend of utilization of re-useable intellectual property (IP) cores for system-on-chip (SOC) design demands an effective, fast and efficient test scheme. This paper presents a unified approach to SOC testing that uses a built-in self-test (BIST) technique based on summations of cores' test output voltages (SOCTOV), which has the advantage of small hardware overhead and fast testing time. The proposed BIST technique is developed in conjunction with our previous proposed BIST technique which is based on weighted sums of selected node voltages (WSSNV) for embedded cores. The WSSNV BIST technique provides high fault coverage for individual cores while the SOCTOV BIST technique provides a 100% fault diagnosis resolution for locating the faulty core. It is an alternative solution to SOC testing especially when chip area overhead is a critical concern.