| 摘要 |
PURPOSE:To obtain an external storage device executing the recovery processing of an error by controlling a lower rank device by an instruction from a higher rank device to write/read out data, and after reading out the error, changing a clock period and executing retrial. CONSTITUTION:When the higher rank device 1 sends a data instruction, an interface circuit 2 sends the instruction to a write/read decoding circuit 3A. The circuit 3A analyzes the sent contents, and if the contents are data writing, sets up a device control circuit 4 to WRITE and sends the data to a device 5. In case of reading, the circuit 3A sets up the circuit 4 to READ, sends the data from the device 5 to the circuit 2 and executes error checking. If an error exists, the circuit 4 sends an error informing signal to the device 1 and the device 1 sends a clock period changing instruction to a clock period changing instruction decoding circuit 3B. The circuit 3B judges the instruction and an incremental direction indicating circuit 6 selects a reducing direction indicating circuit 7, which applies an instruction to change the clock period. The device 1 instructs retrial and the retrial is repeated until no error is checked again. |
