| 摘要 |
PURPOSE:To enable a diagnosis of a defective LSI with a simple logical circuit by comparing the output of each LSI with the output of other LSI by a simultaneous scanning-in of the same pattern data. CONSTITUTION:The outputs of LSIs 5-7 according to the diagnosis data simultaneously scanned in from a diagnosis data generating circuit 14 are compared with the outputs of other two sets of LSIs by respectively comparative circuits 22-24 and in case of dissidence, the outputs of the circuits 22-24 are turned over to a logic 1 and fed to a display controlling circuits 25-27 and a display is lit. A diagnosis is performed as to which LSI is defective with a simple logical construction by the combination of the display lighting. |
