Fault Modeling and Efficient Testing of Memristor-Based Memory

Memristor-based memory technology is one of the emerging memory technologies, which is a potential candidate to replace traditional memories. Efficient test solutions are required to enable the quality and reliability of such products. In previous works, fault models are caused by open, short and bridge defects and parametric variations during the fabrication. However, these fault models cannot describe the bridge defects that cause the state of the faulty cell to an undefined state. In this paper, we analyze the different effects of bridge defects and aggregate their faulty behavior into new fault models, undefined coupling fault and dynamic undefined coupling fault. In addition, an enhanced March algorithm is designed to detect all the modeled faults. In one resistor crossbar with N memristors, the enhanced March algorithm requires 8N write and 7N read operations with negligible hardware overhead. To reduce the test time, a March RC algorithm is proposed based on read operations with new reference currents, which requires 4N + 2 write and 6N read operations. Analytical results show that the proposed test algorithms can detect all the modeled faults outperforming all the previous methods. Subsequently, a Design-for-Testability scheme is proposed to implement March RC algorithm with a little area overhead.

Automated summary

This paper investigates the impact of bridge defects and introduces two new fault models: undefined coupling fault and dynamic undefined coupling fault. An enhanced March algorithm is designed to detect all modeled faults, while a March RC algorithm based on new reference currents is proposed to reduce test time. Analytical results show that the proposed test algorithms outperform previous methods in detecting all modeled faults.