Title :
Fault modeling and testing of retention flip-flops in low power designs
Author :
Bai, Bing-Chuan ; Kifli, Augusli ; Li, Chien-Mo ; Wu, Kun-Cheng
Author_Institution :
Dept. of Electr. Eng., Nat. Taiwan Univ., Taipei
Abstract :
Low power circuits have become a necessary part in modern designs. Retention flip-flop is one of the most important components in low power designs. Conventional test methodologies are not sufficient to test the retention flip-flop thoroughly. This paper presents four new fault models and the testing of retention flip-flop. The four fault models are awake-mode stuck-at fault, sleep-mode stuck-at fault, awake-mode transition fault, and sleep-mode transition fault. The four faults model the defects that affect the retained value, wakeup time, and sleep time of retention flip-flops. Based on the new fault models, test patterns for retention flip-flop can be easily generated by current automatic test pattern generation tools. The proposed test methodology is validated by performing experiments on ISCAS´89 benchmark circuits and some realistic industrial low power designs. The experimental results show that the faults of retention flip-flops can be easily detected by our method and the average fault coverage is higher than 98%. The fault coverage of conventional single stuck-at fault and transition fault test can be increased by more than 1%.
Keywords :
fault diagnosis; flip-flops; logic design; logic testing; low-power electronics; automatic test pattern generation tools; awake-mode transition fault; fault modeling; low power circuits; low power designs; retention flip-flop testing; sleep-mode stuck-at fault; sleep-mode transition fault; test methodologies; Automatic test pattern generation; Automatic testing; Benchmark testing; Circuit faults; Circuit testing; Electrical fault detection; Fault detection; Flip-flops; Performance evaluation; Test pattern generators;
Conference_Titel :
Design Automation Conference, 2009. ASP-DAC 2009. Asia and South Pacific
Conference_Location :
Yokohama
Print_ISBN :
978-1-4244-2748-2
Electronic_ISBN :
978-1-4244-2749-9
DOI :
10.1109/ASPDAC.2009.4796559