| 摘要 |
PURPOSE:To continue the operation of a data transfer circuit without causing a system down by using another normal transmission line to transfer the data in division when the correct transfer of data is impossible due to a partial fault of a certain transmission line. CONSTITUTION:When a higher rank 20 of an error detecting circuit connected to a data line detects an error, the output signal of the rank 20 is reported to a control circuit 24 via a signal line. The circuit 24 receives the report from the rank 20 and knows that a fault is produced at a higher rank of a data transmission line. Then the circuit 24 transfers hereafter the data in division with use of only a lower rank of the data transmission line with production of a control signal and output this control signal to a higher rank 12 of a transmission data selecting circuit, a lower rank 13 of the transmission data selecting circuit, a higher rank 22 of a reception register, and a lower rank 23 of the reception register respectively. Thus the actions of these circuits are controlled. In such a constitution, the operation of a data transfer circuit can be continued without producing a system down. |
