基于电流信息的CMOS SRAM存储单元故障测试

针对深亚微米技术,提出了差分静态电流技术和动态电流技术相结合的方法对CMOS SRAM存储单元进行故障诊断,针对该方法改进了0-1算法。改进的0-1算法与传统的March算法相比,明显降低了测试开销。以四单元存储器为诊断实例,针对桥接故障、开路故障与耦合故障,实现了100%故障诊断覆盖率。实验结果证明了新方法具有故障覆盖率高的特点,能够诊断传统逻辑测试法难以探测的部分故障。

Testing fault in CMOS SRAM circuit based on current signal

Aiming at the technology of very deep sub-micron (VDSM) , the method which combines delta-IDDQ and IDDT to test CMOS SRAM is proposed, and the 0-1 arithmetic for the method is improved. The improved 0-1 arithmetic compared to traditional March arithmetic obviously reduces spending of testing. A sample diagnosis of memory circuit which has four cells reaches 100% fault coverage while tests bridge fault,open fault and coupling fault. The test results certify that the new method has high fault coverage, and can diagnose some fault which traditional logic testing difficultly diagnose.