摘要:
A device for reproducing data recorded on a recording medium, such as a magnetic disk or an optical disk, includes a data reading apparatus and a data reproducing apparatus. The data reading apparatus reads sector data from the reading medium, including data, synch-byte signals and control signals, and generates a clock signal. The data reading apparatus reproduces the recorded data in accordance with the clock signal. When a synch-byte signal is detected by the reading apparatus, transmission of control signals to the reproducing apparatus is inhibited. In addition, lost data is recovered using other data and an ECC code.
摘要:
When a zero run, which violating G constraint of a run-length-limited (RLL) code, is detected from the data stored in a first input register 1111 and a second input register 1112, bits before and after the zero run is transferred to a temporary register 1150 via a bus for zero run removal 1130 to be combined to each other. Thus, by effectively using the mechanism of bus transfer, a circuit can be simplified, thereby realizing a small circuit.
摘要:
A signal processor used to process an analog read signal representing data stored on a magnetic disk allows for a faster read operation without requiring an increase in its circuit area or buffer memory space. The signal processor includes a decision feedback equalizer which selectively provides a feedback signal added to a read signal in reproducing data read from a storage medium. The signal processor also performs error correction. In performing error correction, the load of the error correcting process is detected and the processing speed is altered depending upon the detected load.
摘要:
A signal processing circuit converts a serial analog signal, obtained by sequentially reading data recorded on a disk by a head, to a parallel digital signal to be output. The signal processing circuit also converts an externally input parallel digital signal to a serial analog signal at the time of recording data on the disk and sends the analog signal to the head. The signal processing circuit comprises a converter that converts the serial analog signal of data read from the disk to a serial digital signal and converts the parallel digital signal of externally input data to an analog signal in order to send the analog signal to the head. A shift register converts the serial digital signal received from the converter to a parallel digital signal in a data read mode and converts the parallel digital signal externally input to a serial digital signal to send the serial digital signal to the converter in a data write mode. A processor operates faster than the disk access speed to perform a predetermined reading process on the parallel digital signal received from the shift register to send out the resultant signal and to perform a predetermined writing process on the parallel digital signal externally input to send the resultant signal to the shift register. A program memory, connected to the processor, stores programs associated with the reading process and writing process that are performed by the processor.
摘要:
An encoder includes an encoded-bit-string generating unit that generates a plurality of bit strings encoded by scrambling with respect to an input bit string; a DC-component evaluating unit that selects a bit string having a predetermined width in the bit strings generated by the encoded-bit-string generating unit, while shifting bits one by one or every m-bits, where m is a positive integer, and evaluates the DC component in each of the bit strings selected; and a bit-string extracting unit that extracts a bit string with suppressed DC component from among the bit strings encoded, based on a result of an evaluation by the direct-current-component evaluating unit.
摘要:
A timing recovery unit detects a phase offset and a frequency offset from a head area of reproduction data and initially corrects them. The timing recovery unit stores data in which a head reproduction signal has been made to be discrete by a fixed clock into a buffer. A phase offset detector detects the phase offset from the data head area in parallel with the operation for writing the data into the buffer. At the same time, a frequency offset detector detects the frequency offset from the data head area in parallel with the operation for writing the data into the buffer. A correction value of the detected phase offset and a correction value of the detected frequency offset are initially set into a digital PLL. While the data is read out from the buffer, a frequency lead-in and a phase lead-in are executed in the head area.
摘要:
A signal processor used to process an analog read signal representing data stored on a magnetic disk allows for a faster read operation without requiring an increase in its circuit area or buffer memory space. The signal processor includes a decision feedback equalizer which selectively provides a feedback signal added to a read signal in reproducing data read from a storage medium. The signal processor also performs error correction. In performing error correction, the load of the error correcting process is detected and the processing speed is altered depending upon the detected load.
摘要:
An encoder for an A/D converter includes a plurality of ROM cells connected between bit lines and word lines. Each of the ROM cells is responsive to a word line select signal supplied to a word line associated with each of the ROM cells for supplying a digital output signal according to the word line select signal to a bit line associated with each of the ROM cells. A logic processor is coupled to one of the bit lines and to two of the word lines used to select a ROM cell connected to the bit line. The logic processor produces an output signal indicative of a selection of the ROM cell connected to the bit line, based on word line select signals supplied on the two word lines.
摘要:
An encoder for an A/D converter includes a plurality of ROM cells connected between bit lines and word lines. Each of the ROM cells is responsive to a word line select signal supplied to a word line associated with each of the ROM cells for supplying a digital output signal according to the word line select signal to a bit line associated with each of the ROM cells. A logic processor is coupled to one of the bit lines and to two of the word lines used to select a ROM cell connected to the bit line. The logic processor produces an output signal indicative of a selection of the ROM cell connected to the bit line, based on word line select signals supplied on the two word lines.
摘要:
A product-sum operation unit including a multiplying unit, a pipeline register for loading a multiplication result, an adder unit for adding a summand and either an output of the pipeline register or an addend. A timing signal generating unit generates first and second timing signals (T1, T2) that are synchronized with first and second clocks (CK1, CK2). A first instruction latch loads an instruction synchronously with the first timing signal (T1) to output a first control signal. A second instruction latch loads an instruction loaded in the first instruction latch synchronously with the second timing signal (T2) to output the second control signal. A control signal selector outputs the second control signal in response to the first timing signal (T1), and also outputs the first control signal to the adder unit, in response to the second timing signal (T2).