Enhancing encoding capacity of combinational test stimulus decompressors

作     者：ALAWADHI Nader SINANOGLU Ozgur AL-MULLA Mohammed 

作者机构：Computer Science Department Kuwait University Computer Engineering Department New York University Abu Dhabi 

出 版 物：《Science China(Information Sciences)》 (中国科学:信息科学(英文版))

年 卷 期：2011年第54卷第8期

页      面：1618-1634页

核心收录：

学科分类：0810[工学-信息与通信工程] 08[工学] 080401[工学-精密仪器及机械] 0804[工学-仪器科学与技术] 080402[工学-测试计量技术及仪器] 0835[工学-软件工程] 081002[工学-信号与信息处理] 

主　　题：VLSI test scan-based testing test data compression test pattern encodability add-on blocks 

摘      要：While scan-based compression is widely utilized in order to alleviate the test time and data volume problems,the overall compression level is dictated not only by the chain to channel ratio but also the ratio of encodable *** increasing the number of scan chains in an effort to raise the compression levels may reduce the ratio of encodable patterns,degrading the overall compression *** this paper,we present various methods to improve the ratio of encodable *** methods are based on manipulating the care bit distribution of an unencodable pattern,thereby rendering it compliant with the correlation induced by the decompressor, and thus converting it into an encodable *** proposed transformations,which are simple yet effective,target improvements over fanout and XOR decompressors,while they can be utilized to enhance other types of decompressors, such as multiplexer-based ones;simple nature of these transformations help preserve the simplicity benefits of combinational *** bit manipulation is effected in the form of selective chain delay, selective slice rotate/invert, or both. By developing computationally efficient algorithms and cost-effective hardware blocks for these manipulation methods, we show that the encodability, and thus the compression levels, of stimulus decompressors can be significantly improved through the practical and design flow compatible solution that we propose.