| 摘要 |
PURPOSE:To easily detect not only trouble with a multichip package MCP as the unit but also a faulty chip in the MCP without requiring large-scale hardware by adding a discrimination code to scan path data. CONSTITUTION:A multichip package which consists of plural chips 21 to 2C internally provided with flip flops in the last stage and connecting means and has plural chips 21 to 2C cascaded by scan paths 3 is provided to constitute a trouble detecting system. The discrimination code indicating the value prescribed as a reset time is stored in the flip flop in the last stage. If trouble occurs in LSI chips 21 to 2C or flip flops in chips at the time of impressing a scan clock, normal data is not propagated on scan paths, and a multibit register is added to the last stage of each LSI chip to locate the trouble position. |
