| 摘要 |
PROBLEM TO BE SOLVED: To efficiently and inexpensively execute the scan test of a huge system of parallel computers or the like. SOLUTION: A scan engine 31 exchanges a JTAG signal line to a scan buffer 32 and outputs a control signal SFT to the scan buffer 32. In case of SFT=1, the scan buffer 32 exchanges the JTAG signal line to a routing controller(RTC) 26 and in case of SFT=0, it shifts data while using a scan path composed of the connected JTAG signal line. Thus, since the scan path is hierarchically constituted, only the RTC 26 at one part can be fetched into the scan path. |
