| 摘要 |
PURPOSE:To detect the occurrence of a fault in a logical circuit by an easy test by simultaneously inputting input data selected from among a high-order digit group and a low-order digit group to two (n) bit barrel shifters, detecting the difference of output data after executing the outputted digit movement, and raising an alarm. CONSTITUTION:At the time of a monitor test, a selector 6 selects the input data of a low-order digit group I1 - In as the input data, and inputs the data to an (n) bit barrel shifter 7. The input data of the low-order digit group I1 - In are inputted to an (n) bit barrel shifter 8, and the digit movement is operated only by the number of digits designated by a control signal inputted from a number of moving digit inputting terminal 4 and outputted. A gate circuit 9 interrupts 1 bit digit movement input data from the (n) bit barrel shifter 8 to the (n) bit barrel shifter 7, when a monitor test signal is inputted. A comparator 13 outputs a fault signal to an alarming terminal 12 when the output data of the (n) bit barrel shifters 7 and 8 are not coincident with each other. Thus, the occurrence of the fault in the logical circuit for operating a digit movement operation, can be detected by the easy test. |
