公开(公告)号：US09817068B1

公开(公告)日：2017-11-14

申请号：US14754386

申请日：2015-06-29

Applicant: Cadence Design Systems, Inc.

Inventor： Vivek Chickermane ,  Krishna Vijaya Chakravadhanula ,  Brian Edward Foutz ,  Steev Wilcox ,  Paul Alexander Cunningham ,  David George Scott ,  Louis Christopher Milano ,  Dale Edward Meehl

IPC: G01R31/3177 ,  G01R31/3181 ,  G01R31/3183 ,  G01R31/3185 ,  G01R31/319

CPC classification number: G01R31/31813 ,  G01R31/318335 ,  G01R31/318385 ,  G01R31/318544 ,  G01R31/318547 ,  G01R31/31921

Abstract: Systems and methods efficiently bring additional variables into a Pseudo-Random Pattern Generator (“PRPG”) in the early cycles of an automatic test pattern generation (“ATPG”) process without utilizing any additional hardware or control pins. Overscanning (e.g., scanning longer than the length of the longest channel) for some additional cycles brings in enough variables into the PRPG. Data corresponding to earlier cycles of the ATPG process is removed.

公开(公告)号：US09470754B1

公开(公告)日：2016-10-18

申请号：US14737331

申请日：2015-06-11

Applicant: Cadence Design Systems, Inc.

Inventor： Vivek Chickermane ,  Krishna Vijaya Chakravadhanula ,  Brian Edward Foutz ,  Steev Wilcox ,  Paul Alexander Cunningham ,  David George Scott ,  Louis Christopher Milano ,  Dale Edward Meehl

IPC: G01R31/28 ,  G01R31/3177

CPC classification number: G01R31/318335 ,  G01R31/3177 ,  G01R31/318547

Abstract: Systems and methods disclosed herein provide for utilizing extra variables in the decompression equation set of an ATPG process for test patterns requiring an excess number of care bits than can be supported efficiently by the current hardware. An elastic interface is utilized between a tester and a decompressor network (e.g., sequential and combinational decompressors) in order to expand the test pattern length and/or the number of input variables. The systems and methods also provide care bits in early scan cycles of the ATPG process for sequential decompressors starting from a fixed state.

Abstract translation: 本文公开的系统和方法提供了在ATPG过程的解压缩方程组中利用额外的变量，用于需要超过当前硬件有效支持的多余护理位的测试模式。 在测试器和解压缩器网络（例如，顺序和组合解压缩器）之间使用弹性接口，以便扩展测试图案长度和/或输入变量的数量。 这些系统和方法还在ATPG过程的早期扫描周期中为从固定状态开始的顺序解压缩器提供护理位。