Low power logic BIST with high test effectiveness

Abstract

Excessive test power has been a serious concern in BIST techniques. Shift power consumption can be significantly reduced by increasing the correlation among adjacent test data bits. However, this method may cause fault coverage loss. This paper presents a novel low power BIST scheme that reduces toggle probability of the scan input data while only shifting out part of capture responses for fault analysis and using the rest of capture responses as new test data. Using part of capture responses as test data can improve uniform distribution of 1s and 0s in test stimulus bits and thus result in high test effectiveness. Experimental results on larger benchmark circuits of ISCSAS89 and ITC99 show that the proposed strategy can reduce significantly test power while suppressing test coverage loss.