Low Power Test Compatibility Classes: Exploiting Regularity for Simultaneous Reduction in Test Application Time and Power Dissipation

Traditional DFT methodologies increase useless power dissipation during testing and are not suitable for testing low power VLSI circuits leading to lower reliability and manufacturing yield. Traditional test scheduling approaches based on fixed test resource allocation decrease power dissipation at the expense of higher test application time. On the one hand it was shown that power conscious test synthesis and scheduling eliminate useless power dissipation. On the other hand by exploiting regularity in BIST RTL data paths using test compatibility classes an improvement in test application time, BIST area overhead, performance degradation, volume of test data, and fault escape probability is achieved. This paper shows that when combining power conscious test synthesis and scheduling with the test compatibility classes into low power test compatibility classes, simultaneous reduction in test application time and power dissipation is obtained.