| 摘要 |
PURPOSE:To enable self diagnosing of an integrated circuit by selecting output signals of each register according to the number of input signals of the part of the circuit that becomes an object of inspection. CONSTITUTION:In the case where diagnostic system of the part of a circuit having the number of input signals (m), it is enough to select (m) output signals of a shift register 1. For instance, supposing that output signals of registers 11-1m are to be selected, switching signals of logic '1' are supplied to switching circuits 101-10m of a switching logical circuit 10, and switching signals of logic '0' are supplied to switching circuits 10m+1-10n through a signal line 7. At the same time, set and reset signals are supplied from a signal line 5 to registers 11-1m, and only the register 11 of the first stage is set to logical value '1' and all other registers 12-1m are set to logical value '0'. Then, clock pulses are inputted successively from a clock signal line 8, and a pseudo random pattern is supplied from the signal line 6 of registers 11-1m of the first step to m-th step to the part of a circuit to be diagnosed, and self-diagnosis of an integrated circuit is performed. |
