摘要:
In one embodiment, a write/read apparatus includes an external interface section for data input; an external interface section for data output; a memory for temporarily storing the data that is input through the external interface section for data input and written on the recording medium and the data that is read from the recording medium and sent to the outside through the external interface section for data output; an address generating section for generating unique addresses associated with physical block addresses of the recording medium; a flag generating section for generating flags for prohibiting overwriting of the data to be written on the recording medium; and a processing section for adding the unique addresses generated in the address generating section to the data that is stored in the memory and that is to be written on the recording medium. The data with the addition of the flags generated in the flag generating section and the unique addresses is written on the recording medium.
摘要:
In one embodiment, a write/read apparatus includes an external interface section for data input; an external interface section for data output; a memory for temporarily storing the data that is input through the external interface section for data input and written on the recording medium and the data that is read from the recording medium and sent to the outside through the external interface section for data output; an address generating section for generating unique addresses associated with physical block addresses of the recording medium; a flag generating section for generating flags for prohibiting overwriting of the data to be written on the recording medium; and a processing section for adding the unique addresses generated in the address generating section to the data that is stored in the memory and that is to be written on the recording medium. The data with the addition of the flags generated in the flag generating section and the unique addresses is written on the recording medium.
摘要:
Embodiment of the present invention provide a technique for carrying out work in a short time to prevent without fail data stored in a read/write device from leaking to persons other than an authorized user. There are provided a read/write device, and a format management method for managing a format of data stored in the read/write device. A given change factor is specified for a format of data stored in the read/write device. A format change judgment part for judging whether or not the change factor exists is provided in the read/write device or in a host device connected to the read/write device. Then, a given offset coefficient is generated for a format table according to an instruction from a format change judgment part, and a different format table is generated according to the generated offset coefficient and the format table.
摘要:
Embodiments of the invention increase the convenience of a magnetic disk drive for portable use by shortening a period of time required to record a large amount of data, and by increasing the reproduction time, in the magnetic disk drive. In one embodiment, an area between servo data parts is interpolated by servo data parts, each of which stores a burst signal, so that the allocation density of a burst signal is made k times. At the time of write operation in which data is written, only the servo data parts are made use of to perform the servo control while a disk is driven at high rotational speed so as to reduce the recording time. At the time of read operation in which data is reproduced, the servo data parts are made use of to ensure the required precision of the servo control at low rotational speed that is 1/k of the rotational speed at the time of write operation. The reproduction at low rotational speed enables the reduction in power consumption.
摘要:
An AGC circuit is provided with a variable gain amplifier which changes an amplification gain of an input signal in accordance with an instruction; an extraction unit for extracting a value of an output of the variable gain amplifier at a predetermined interval; and a variable gain control unit for instructing the amplification gain of the variable gain amplifier in a manner such that the amplitude of the input signal is equal to a predetermined amplitude on the basis of the value extracted by the extraction unit. The variable gain control unit is provided with an error signal output device for squaring the value extracted by the extraction unit and for generating an error signal to instruct the amplification gain of the variable gain amplifier in a manner such that the amplitude of the input signal is equal to a predetermined amplitude on the basis of the square value and a square value just before it; and an integrating device for integrating the error signal from the error signal output device and for instructing the amplification gain of the variable gain amplifier.
摘要:
Embodiments of the invention increase the convenience of a magnetic disk drive for portable use by shortening a period of time required to record a large amount of data, and by increasing the reproduction time, in the magnetic disk drive. In one embodiment, an area between servo data parts is interpolated by servo data parts, each of which stores a burst signal, so that the allocation density of a burst signal is made k times. At the time of write operation in which data is written, only the servo data parts are made use of to perform the servo control while a disk is driven at high rotational speed so as to reduce the recording time. At the time of read operation in which data is reproduced, the servo data parts are made use of to ensure the required precision of the servo control at low rotational speed that is 1/k of the rotational speed at the time of write operation. The reproduction at low rotational speed enables the reduction in power consumption.
摘要:
A reproduced signal processing circuit includes a variable gain amplifier to which a signal read from a medium by a reproducing head is inputted; an analog-to-digital converter for converting a signal outputted from the variable gain amplifier into a digital signal; and a variable frequency oscillator for supplying an operation clock signal to the analog-to-digital converter. A reproduced signal processing method includes the steps of operating a first control loop for controlling the variable gain amplifier; operating at least either one of a second control loop and a third control loop, the second control loop controlling the variable frequency oscillator, the third control loop controlling the variable frequency oscillator; filtering by analog filter means the read signal inputted to the variable gain amplifier; operating at least one of first, second, and third noise detecting operations, the first noise detecting operation detecting presence or absence of a noise by comparing an amplitude of the output signal from the variable gain amplifier with a predetermined threshold value, the second noise detecting operation detecting a noise during an operation period of the second control loop, the third noise detecting operation detecting a noise during an operation period of the third control loop; and changing the range of cutoff frequency of the analog filter means in accordance with a result from at least one of the first, second, and third noise detecting operations, thereby controlling at least one of the first, second, and third control loops.
摘要:
A clock timing extraction circuit for use in an information recording/reproducing apparatus has a phase comparator for comparing the reproduced signal with a selected clock signal to generate a phase error signal, a clock signal generation circuit for adjusting frequency to cause the error signal to approach zero according to the phase error signal and outputting a plurality of clock signals having mutually different phase differences, a selection circuit for outputting one of the plurality of clock signals on the basis of a selection signal, a phase difference judgement circuit for determining one of the plurality of clock signals having a minimum phase error (Vdet) and generating a selection signal for selection of the clock signal having the minimum phase difference, and a freeze circuit for blocking an output of the phase comparator until the clock signal having the minimum phase error is selected. The information recording/reproducing apparatus has an AGC circuit for limiting an amplitude of a reproduced signal received from a recording medium, the aforementioned clock timing extraction circuit, and a decoder circuit. The clock timing extraction circuit extracts a clock signal from an output signal of the AGC circuit and the decoder decodes the output signal of the AGC circuit on the basis of the extracted clock signal.
摘要:
Embodiments of the invention increase the convenience of a magnetic disk drive for portable use by shortening a period of time required to record a large amount of data, and by increasing the reproduction time, in the magnetic disk drive. In one embodiment, an area between servo data parts is interpolated by servo data parts, each of which stores a burst signal, so that the allocation density of a burst signal is made k times. At the time of write operation in which data is written, only the servo data parts are made use of to perform the servo control while a disk is driven at high rotational speed so as to reduce the recording time. At the time of read operation in which data is reproduced, the servo data parts are made use of to ensure the required precision of the servo control at low rotational speed that is 1/k of the rotational speed at the time of write operation. The reproduction at low rotational speed enables the reduction in power consumption.
摘要:
Embodiments of the present invention efficiently format long sectors, without decreasing the performance, in a magnetic disk drive in which servo sectors are radially formed at regular intervals, and make full use of the ECC performance that is enhanced by the long sectors. In one embodiment, a data format in each zone on a magnetic disk is completed by a plurality of tracks N (N is an integer, which is 2 or more). The storage capacity per track of the outermost radius zone Z#1 is 150 kB. In this zone, long sectors each having a length of 32 kB are formatted with the number of tracks per format N#1=3. The storage capacity per track of the innermost radius zone Z#m is 80 kB. In this zone, long sectors each having a length of 32 kB are formatted with the number of tracks per format N#n=2.