基于扫描链阻塞技术的时延测试方法

针对时延测试功耗和测试费用较高的问题，提出一种低费用的轮流捕获时延测试方法。采用扫描阻塞技术，将被测电路中的所有扫描单元分成多条子扫描链，使电路中每时刻只有一条子扫描链活跃。在进行故障测试时，通过阻塞一部分子扫描链，使扫描单元得到充分利用。实验结果表明，该方法能降低测试应用时间和测试数据量，且硬件开销较少。

Delay Test Method Based on Scan Chain Blocking Technique

In order to solve the high test cost and high test power, the study proposes a low cost test method. Using scan chain blocking technique, all sequence elements are divided into N scan sub-chains and only one scan sub-chain is active at a time during scan test. Not all elements need to be active in test. The division of sub-chain makes some sequence elements inactive in test model and make full use of scan elements. Experimental result demonstrates that the method can drastically reduce test application time with a low cost on hardware.