Abstract: According to one embodiment, a read/write apparatus includes a receiver and a refresh module. The receiver receives a write command requesting a write to a magnetic disk. The refresh module refreshes, when a first area of the magnetic disk includes a second area corresponding to the write command, data written in a third area, the third area being an area obtained by excluding the second area from the first area.

Abstract: According to one embodiment, a read/write apparatus includes a receiver and a refresh module. The receiver receives a write command requesting a write to a magnetic disk. The refresh module refreshes, when a first area of the magnetic disk includes a second area corresponding to the write command, data written in a third area, the third area being an area obtained by excluding the second area from the first area.

Abstract: Firmware FW1 and FW2 is separately stored in a non-volatile memory, in which a boot code for start-up and a restoration code are stored, and a first magnetic disk. A copy of the firmware FW1 stored in the non-volatile memory is stored in the first magnetic disk, and a copy of the entire firmware FW1 and FW2 stored in the first disk medium is stored in the second magnetic disk. When an error occurs during firmware update, upon next power-on, whether the volatile memory, the first magnetic disk, and the second magnetic disk are normal or abnormal is determined, and valid firmware is read and allocated to the volatile memory so as to perform start-up by a start-up mode corresponding to the determination contents.

Abstract: Firmware FW1 and FW2 is separately stored in a non-volatile memory, in which a boot code for start-up and a restoration code are stored, and a first magnetic disk. A copy of the firmware FW1 stored in the non-volatile memory is stored in the first magnetic disk, and a copy of the entire firmware FW1 and FW2 stored in the first disk medium is stored in the second magnetic disk. When an error occurs during firmware update, upon next power-on, whether the volatile memory, the first magnetic disk, and the second magnetic disk are normal or abnormal is determined, and valid firmware is read and allocated to the volatile memory so as to perform start-up by a start-up mode corresponding to the determination contents.

Abstract: Firmware FW1 and FW2 is separately stored in a non-volatile memory, in which a boot code for start-up and a restoration code are stored, and a first magnetic disk. A copy of the firmware FW1 stored in the non-volatile memory is stored in the first magnetic disk, and a copy of the entire firmware FW1 and FW2 stored in the first disk medium is stored in the second magnetic disk. When an error occurs during firmware update, upon next power-on, whether the volatile memory, the first magnetic disk, and the second magnetic disk are normal or abnormal is determined, and valid firmware is read and allocated to the volatile memory so as to perform start-up by a start-up mode corresponding to the determination contents.

Abstract: A storage apparatus divides and stores firmware which is drive control software to record and reproduce data in a disk medium into a non-volatile memory and a disk medium, and at the time of activating the apparatus, stores and executes firmware read from the non-volatile memory and the disk medium into a volatile memory. A renewal request processing unit, when received a renewal request of the firmware from a host, advises the host of the renewal completion at a point of time when new firmware transferred from the host is received and stored in the buffer memory. The background renewal unit, after the advice of the renewal completion, writes and renews the new firmware into the non-volatile memory and the disk medium as a background processing using the processing idle time of a command issued by the host.

Abstract: In a rotation synchronous control system comprising a host controller and a plurality of units connected to the host controller, each of the plurality of units having a rotation device, the system having a spindle sync function for the rotation devices to maintain a spindle sync between them, each of the units is provided with a spindle sync/reference signal source and a phase adjuster. The controller monitors the spindle sync between the units and issues a phase correction instruction to each of the units. Receiving the instruction, the phase adjuster in each unit adjusts the phase of the sync signal and uses the sync signal thus corrected to provide a spindle sync control.

Abstract: A control unit, such as an MPU in an external storage device or external storage control device, detects, on the basis of a Read or Write command, whether or not an internal reading or writing velocity is changed from one value to another value according to a zone of a storage medium. When the velocity is changed, the control unit calculates an optimal buffer full ratio or buffer empty ratio suitable for the velocity and sets the ratio in a data buffer control unit. Moreover, the control unit, such as an MPU, determines whether or not data requested by the Read or Write command resides over different zones in the storage medium. When the data resides over different zones, the control unit calculates one zone containing a majority of the requested data, works out an optimal buffer full ratio or buffer empty ratio according to a medium transfer rate associated with the zone, and sets the ratio in the data buffer control unit.

Abstract: In a rotation synchronous control system comprising a host controller and a plurality of units connected to the host controller, each of the plurality of units having a rotation device, the system having a spindle sync function for the rotation devices to maintain a spindle sync between them, each of the units is provided with a spindle sync/reference signal source and a phase adjuster. The controller monitors the spindle sync between the units and issues a phase correction instruction to each of the units. Receiving the instruction, the phase adjuster in each unit adjusts the phase of the sync signal and uses the sync signal thus corrected to provide a spindle sync control.

Abstract: An object of the present invention is to minimize an overhead attributable to internal control and to provide a CDR type disk unit in which even when a head moves over a zone boundary, a sector pulse indicating a destination sector can be generated reliably without waiting for an index pulse. The disk unit includes a processing unit; a sector pulse generation unit which generates a sector pulse according to a signal written in the servo information on medium surface; and a format control unit which starts the formatting control when said sector pulse is received after a activating command is received from said processing unit; a target sector detection unit which detects the instant when said head reaches the target sector. The sector pulse generation unit stops outputting the sector pulses to the format control unit from when the access operation starts until a target pulse is received from the target sector detection unit.