Abstract: A serial transmission system performs data transfer between a first port and a second port via a transmission path. The first port includes a receiving unit that receives data, a signal-quality measuring unit that measures the signal quality of receive data, a correction-request-data generating unit that generates correction request data for correcting output characteristics of the second port on the basis of a result of the measurement, and a sending unit that sends the generated correction request data. The second port includes a sending unit that sends data, a receiving unit that receives the correction request data from the first port, and a setting unit that changes settings of output characteristics of the sending unit on the basis of the received correction request data.

Abstract: In a data processing device, a processor processes data based on a stored program and a buffer manager accesses the data. The data processing device includes a program memory which stores program codes, the program codes being loaded into the program memory and executed by the processor when processing the data. A shared memory stores one of the program codes and the data. A control unit selectively connects one of the processor and the buffer manager to the shared memory based on a select pattern, wherein the shared memory functions to store the program codes when the select pattern is set in a first condition, and the shared memory functions to store the data when the select pattern is set in a second condition.

Abstract: A magnetic disk sub-system composed of a plurality of magnetic disk drives comprises a rotation synchronizing control circuit, where the rotations of the spindle motors of a plurality of magnetic disk drives are synchronized. By distributing/allocating a data position to a different address on each drive, rotations can be synchronized, and if the data is read from a head, the concurrence of a plurality of segments of data transfer can be prevented by shifting the timing in which the data is actually read from each disk.

Abstract: In a data processing device, a processor processes data based on a stored program and a buffer manager accesses the data. The data processing device includes a program memory which stores program codes, the program codes being loaded into the program memory and executed by the processor when processing the data. A shared memory stores one of the program codes and the data. A control unit selectively connects one of the processor and the buffer manager to the shared memory based on a select pattern, wherein the shared memory functions to store the program codes when the select pattern is set in a first condition, and the shared memory functions to store the data when the select pattern is set in a second condition.

Abstract: Logical tracks having a constant capacity are composed of combinations of physical tracks in a plurality of disks. For example, in a case where the data recording region of the first disk is divided into three zones A, B, C and that of the second disk is divided into three zones A', B', C', the physical tracks of outer zone A and inner zone C', middle zones B and B' and inner zone C and outer zone A' are combined, respectively. A host apparatus issues a read/write command by using a logical track address, and a track address converter converts the logical track address into a plurality of physical track addresses. A magnetic disk controlling apparatus writes the entire part of a record instructed to be written by the host apparatus in a physical track in one magnetic disk apparatus, or splits the record into two portions and consecutively writes them into physical tracks of both magnetic disks.

Abstract: A method of restoring write data in a disk cache system includes the steps of providing a host, a disk drive having a plurality of tracks including a plurality of records, a cache memory, a nonvolatile memory storing a directory which controls storing of tracks within the nonvolatile memory, and a disk controller. The disk controller writes tracks of data from the disk drive, including records addressed by a read command sent from the host, into the cache memory. The disk controller also writes tracks of data, including records updated by the host, into the nonvolatile memory in response to a write command sent from the host, and restores the records updated by the host to the disk drive during an idle time of the disk drive. A record in the nonvolatile memory is updated in response to the write command sent from the host. A start address and an end address of a record to be restored to the disk drive from the nonvolatile memory are updated in response to an address of a record updated by the host.

Abstract: A diagnostic system for diagnosing a number of connected modules within a data processing system. The diagnostic system uses one module as a management module to diagnose other function modules. A function module can be designated to recognize only diagnostic data by storing a diagnostic command within that module. By recognizing only nondiagnostic data, the other function modules can continue normal operation without interruption by the diagnosis.