摘要:
In a perpendicular magnetic recording system, the data that is being written by the write channel is fed back into the read channel. The read channel processes the data and decides if the written sequence is likely to have very poor DC characteristics. If that is the case, the write channel changes a scrambler seed and rewrites the data using the new scrambler seed. The data may also be inspected for patterns that might cause large baseline wander before being written to disk, i.e., in the write channel. A data sequence may be repeatedly scrambled and encoded until an acceptable level of estimated DC-wander has been achieved. The data sequence may then be written to disk.
摘要:
A communication system includes a variable gain amplifier (VGA) that receives an input signal. An analog-to-digital converter (ADC) receives an output of the VGA. A first filter responsive to an output of the ADC, the first filter includes N tap weight coefficients. A first least mean square (LMS) engine updates the N tap weight coefficients of the first filter. A second filter responsive to an output of the first filter, the second filter including M tap weight coefficients, wherein N is greater than M. An adaptation engine updates a first tap weight coefficient of the second filter based on a value of the first tap weight coefficient for a next sampling time of the input signal, a value of the first tap weight coefficient for a current sampling time of the input signal, a first gain constant, and a change in timing phase error of the first filter.
摘要:
A solid state non-volatile memory unit includes, in part, an encoder, a multi-level solid state non-volatile memory array adapted to store data encoded by the encoder, and a decoder adapted to decode the data retrieved from the memory array. The memory array may be a flash EEPROM array. The memory unit optionally includes a modulator and a demodulator. The data modulated by the modulator is stored in the memory array. The demodulator demodulates the modulated data retrieved from the memory array.
摘要:
A tracking system for an optical drive includes a focus error module. The focus error module generates a focus error signal based on a difference between a first sensor output signal and a second sensor output signal, which are based on a reflected portion of a laser beam that is reflected by an optical storage medium. A control module generates a tracking signal based on the focus error signal.
摘要:
An apparatus includes a LED and a regulator circuit. The regulator circuit controls the current provided to the LED according to a calibration signal that is coupled to the current. The regulator circuit adjusts the output of the LED when the calibration signal is adjusted. In this manner, the LED may be calibrated to generate light at a desired brightness level and color level.
摘要:
A hard disk controller (HDC) of a hard disk drive (HDD) includes a read module, a clock generator module, and a write module. The read module reads servo spirals from a magnetic medium of the HDD via a read head of the HDD and generates read signals. The clock generator module generates a spiral clock having a first frequency based on the read signals and generates based on the spiral clock R write clocks having R frequencies, respectively, that are different than the first frequency, where R is an integer greater than 1. The write module writes via a write head of the HDD a first servo wedge on a first one of R zones of the magnetic medium using a first one of the R write clocks and a second servo wedge on a second one of the R zones using a second one of the R write clocks.
摘要:
An integrated circuit including a voltage generator and a control module. The voltage generator is configured to generate a first voltage based on a plurality of codewords, and output the first voltage to a first word line communicating with a first set of transistors. Each of the first set of transistors has a plurality of programmable threshold voltages. The control module is configured to determine values of the threshold voltages of the first set of transistors based on (i) the codewords and (ii) currents sensed through the first set of transistors in response to the first voltage being output to the first word line. The control module is configured to adjust the values of the threshold voltages of the first set of transistors based on at least one of (i) locations of the first set of transistors on the first word line and (ii) a temperature of the integrated circuit.
摘要:
Systems and techniques to configure a read channel include, in at least one implementation, an apparatus including: detection circuitry configured to process an input signal from a machine-readable medium to calculate metrics; monitoring circuitry configured to determine a polarity of the input signal based on the metrics and at least one of multiple framings of signal samples of the input signal; and selection circuitry to configure a read channel for the machine-readable medium based on the determined polarity.
摘要:
A method of producing capacitor structure includes, in at least one aspect, arranging first layer, adjacent first and second polarity conducting strips, the first layer conducting strips arranged as respective piecewise “S” shaped paths; arranging second layer, adjacent first and second polarity conducting strips, the second layer conducting strips arranged as respective piecewise “S” shaped paths, the second layer second polarity conducting strip is arranged overlying and electrically separated from the first layer first polarity conducting strip, and the second layer first polarity conducting strip is arranged overlying and electrically separated from the first layer second polarity conducting strip; electrically connecting the first layer first polarity conducting strip with the second layer first polarity conducting strip; and electrically connecting the first layer second polarity conducting strip with the second layer second polarity conducting strip.
摘要:
A method for testing operation of a preamplifier circuit includes generating a first symbol, converting the first symbol into a write signal, transmitting the write signal to a write signal input of the preamplifier circuit, and looping the write signal back to a read signal output of the preamplifier circuit.