| 摘要 |
PURPOSE:To discriminate whether or not an input/output request of a computer has completed after disconnecting a power source or after restoration by providing a status control circuit and a status holding circuit. CONSTITUTION:The device consists of a status control circuit 10, a status holding circuit 20, an external storage device driving circuit 30 and a battery 40, and is provided with an interface 100 between the computer and the external storage device control circuit and an interface 200 between the external storage device control circuit and the external storage device. The status control circuit 10 controls the status of the external storage device, and the status holding control circuit 20 holds the status contents by means of the battery 40 even at the time of power disconnection. When the computer requests an input/output from the external storage device, the status holding circuit 20 retains the fact that the input/output request is made and the fact that the request has completed. Then after the power disconnection and restoration, by retrieving the status holding circuit 10, whether or not the request of the computer has completed can be decided. |
