多芯片组件(MCM)的可测性设计

为克服在线测试技术测试MCM时不能达到满意的故障覆盖率的困难，采用可测性技术对MCM进行设计．根据MCM的特点和测试要求，提出了在JTAG标准基础上扩展指令寄存器，添加专门的用户指令，融合扫描通路法、内建自测试法等可测性方法，分层次地对MCM进行全面测试．建立模型进行验证的结果表明：该方法能有效地测试MCM，缩短了测试时间，故障覆盖率达到95％以上．

Design for Testability of Multi Chip Module(MCM)

To overcome the difficulties in achieving satisfactory fault coverage when testing Multi Chip Module (MCM), MCM was designed by means of testability technology using on-line test technique. According to the characteristics of MCM and its testing requirements, a testing solution based on extending JTAG through adding instruction registers and user instructions was proposed. It embraced some techniques of designing for testability (DFT), such as Scan-based Test and Build-in Self Test (BIST). Tests results showed that this method could test MCM effectively at a shorter time with a fault coverage of more than 95%.