| 摘要 |
PURPOSE:To make it possible to dividing and executing the diagnosis of the arithmetic circuit, by adding the memory element for logically cutting a carry signal, in the adding circuit for adding 2 or 3 inputs. CONSTITUTION:The arithmetic circuit 3 brings a variation to the contents of the output latch group 4 depending on the inputs of the input latch groups 1, 2, and the value of a carry signal 8 showing whether there exists the other carry or not. The carry signal 8 is an output of the carry forecasting circuit 7, and in order to decide the value of the carry signal, the value concerning all the input latch sequences must be decided. However, the operator 3 can be made a closed circuit by suppressing the carry forecasting signals 5, 6 to the diagnostic control signal 91 and providing the diagnostic input latches 96, 97 instead of them. Also, if the diagnostic output latches 98, 99 are provided so that the contents of the carry forecasting signals 5, 6 can be reflected, normalness of the carry forecasting circuit can be confirmed entirely without depending on the operation. |
