| 摘要 |
PURPOSE:To detect easily and surely missing of a ready signal without applying a load on the firmware in the titled device by providing a circuit judging the presence of the missing of the ready signal from the state of change in the ready signal and a ready signal missing detection circuit comprising storing the information being the result of judging. CONSTITUTION:The ready signal missing detection 15, if a drive select signal changes from the selecting state into the non-selecting state due to any cause, confirms the state to be consecutive for a prescribed time, holds a ready signal returned from corresponding magnetic disk devices 2<1>, 2<2> attended with the issue of an alternate drive select signal generated in the inside in place of the drive select signal, judges the presence of generation of the loss of the ready signal from the state transition of the ready signal to hold the information being the result of judgment. The information being the result of judgment held by the ready signal missing detection circuit 15 is read by a microprocessor 11 in a controller 1 to detect the loss of ready signal surely and easily.
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