| 摘要 |
PURPOSE:To set an optional value in the specific gate circuit of a device to be tested by providing a testing device with an optional value scan-in control circuit which controls scan-out control part and a scan-in control part at the same time. CONSTITUTION:A scan-in (Sin) signal from the scan-in control part 30 in the testing device 20 is inputted to a flip-flop F111 in the device 10 to be tested, and an output value (SCAN) is sent out. This is returned into the testing device 20 together with output values of FFs 112 and 113, and an FF output address selecting circuit 27 makes a selection by the scan-out control part 26. An optional value scan-in setting circuit 25 which sets an optional value is provided to control both control parts. An optional value scan (Fsin) instruction is sent to the optional value scan-in setting circuit 25, and the set optional value scan-in signal is sent to the scan-out control part 26 to perform scan-out control. |
