JP2009158045A - Test code output method and test code output device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique for highly frequently generating a particular pattern signal without using a dedicated circuit. <P>SOLUTION: This test code output method selects a data word A (h: hexadecimal number system) corresponding to a desired code word from a demodulation table, detects a state N for the desired code word corresponding to the data word A from a modulation table, detects a code word made to correspond to the next state information for designating the state N as the next state, including an odd number of bits 1 from the modulation table, selects a data word B (h: hexadecimal number system) corresponding to the detected code word, and outputs a test code generated by modulating a test data word including a plurality of data words B and A. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a modulation recording technique for modulating and recording an n-bit data word into an m-channel bit code word. More particularly, the present invention relates to a modulation recording technique using 8/12 modulation (ETM: Eight to Twelve Modulation) that modulates an 8-bit data word into a 12-channel bit code word.

A technique for modulating a data word into a code word and recording it on an optical disk is known. In addition, there has been proposed a method for optimizing recording conditions by recording a specific pattern signal on an optical disc, reproducing the specific pattern signal, and evaluating the reproduction signal (see Patent Document 1).
JP 2002-319130 A

  However, the conventional recording condition optimization technique described above requires a dedicated circuit for generating the specific pattern signal. That is, it is necessary to generate a specific pattern signal by a dedicated circuit. More specifically, it is difficult to generate a specific pattern signal at a high frequency unless a dedicated circuit is used.

  An object of the present invention is to provide a technique capable of generating a specific pattern signal at a high frequency without using a dedicated circuit.

  The test code output method of the present invention is a test code output method using a modulation table for modulating various data words into code words, wherein the modulation table corresponds to each of the various data words. Code state selected in 0 and next state information designating one of the next states 0, 1 and 2; Code word selected in state 1 and any of the next states 0, 1 and 2 Data from the code word modulated by the modulation table, and the next state information designating one of the next states 0, 1, and 2 From the demodulation table for demodulating the word, the data word A (A: two-digit hexadecimal number) corresponding to the desired code word And the state N (N = 0, 1, 2) of the desired code word corresponding to the data word A is detected from the modulation table, and the state N is determined as the next state from the modulation table. A code word corresponding to the designated next state information and including an odd number of bits 1 is detected, and a data word B (B: two-digit hexadecimal number) corresponding to the detected code word And a test code generated by modulating a test data word including a plurality of data words B A is output.

  A test code output device according to an embodiment of the present invention includes a modulation table for modulating various data words into code words, and a demodulation table for demodulating data words from the code words modulated by the modulation table. Storage means for storing, and a test code generated by modulating a test data word including a plurality of data words B A (A, B: two-digit hexadecimal numbers) generated based on the modulation table and the demodulation table The modulation table includes a code word selected in state 0 and a next state designating one of the next states 0, 1 and 2 corresponding to each of various data words. Information, the code word selected in state 1 and the next step designating one of the next states 0, 1, 2 And the next state information designating one of the next states 0, 1, and 2, and the output means receives a desired codeword from the demodulation table. Is selected from the modulation table, and the state N (N = 0, 1, 2) of the desired code word corresponding to the data word A is detected from the modulation table. A code word associated with next state information designating the state N as a state and including an odd number of bits 1 is detected, and a data word B corresponding to the detected code word is selected. The data word B A is generated.

  ADVANTAGE OF THE INVENTION According to this invention, the technique which makes it possible to generate a specific pattern signal with high frequency, without using a dedicated circuit can be provided.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram showing a schematic configuration of an optical disc apparatus (test code output apparatus) according to an embodiment of the present invention. For example, the optical disk device records information on an optical disk D such as an HD DVD or reproduces data recorded on the optical disk D.

  As shown in FIG. 1, the optical disc apparatus includes an optical pickup 10, a modulation circuit 21, a recording / reproduction control unit 22, a laser control circuit 23, a signal processing circuit 24, a demodulation circuit 25, an actuator 26, a focus / tracking control unit 30, and a host. A computer (data word generator) 40 is provided.

  The optical pickup 10 includes a laser 11, a collimating lens 12, a polarization beam splitter (hereinafter referred to as PBS) 13, a quarter-wave plate 14, an objective lens 15, a condensing lens 16, and a photodetector 17.

  First, recording of information on the optical disc D by the optical disc apparatus will be described. The modulation circuit 21 modulates an 8-bit data word provided from the host computer 40 into a 12-channel bit data code according to the modulation tables shown in FIGS. 3A to 3E. The data code is input to the recording / playback control unit 22. Further, a recording / reproducing instruction (in this case, a recording instruction) from the host computer 40 is input to the recording / reproducing control unit 22. The recording / reproducing control unit 22 outputs a control signal to the actuator 26 and drives the optical pickup so that the light beam is appropriately condensed at the target recording position. Further, the recording / reproducing control unit 22 supplies the data code to the laser control circuit 23. The laser control circuit 23 converts the data code into a laser drive waveform and drives the laser 11. That is, the laser control circuit 23 drives the laser 11 in pulses. Along with this, the laser 11 irradiates a recording light beam corresponding to a desired data code. The recording light beam emitted from the laser 11 is converted into parallel light by the collimator lens 12, enters the PBS 13, and passes therethrough. The beam that has passed through the PBS 13 passes through the quarter-wave plate 14 and is focused on the information recording surface of the optical disc D by the objective lens 15. The condensed light beam for recording is maintained in a state where the best minute spot can be obtained on the recording surface by the focus control / tracking control by the focus / tracking control unit 30 and the actuator 26.

  Next, reproduction of data from the optical disc D by this optical disc apparatus will be described. A recording / playback instruction (in this case, a playback instruction) from the host computer 40 is input to the recording / playback control unit 22. The recording / reproduction control unit 22 outputs a reproduction control signal to the laser control circuit 23 in accordance with a reproduction instruction from the host computer 40. The laser control circuit 23 drives the laser 11 based on the reproduction control signal. Accordingly, the laser 11 irradiates a reproduction light beam. The reproduction light beam emitted from the laser 11 is converted into parallel light by the collimator lens 12, enters the PBS 13, and is transmitted therethrough. The light beam that has passed through the PBS 13 passes through the quarter-wave plate 14 and is focused on the information recording surface of the optical disc D by the objective lens 15. The condensed light beam for reproduction is maintained in a state where the best minute spot can be obtained on the recording surface by the focus control / tracking control by the focus / tracking control unit 30 and the actuator 26. At this time, the reproducing light beam irradiated on the optical disk D is reflected by the reflective film or the reflective recording film in the information recording surface. The reflected light passes through the objective lens 15 in the reverse direction and becomes parallel light again. The reflected light passes through the quarter-wave plate 14, has a polarization perpendicular to the incident light, and is reflected by the PBS 13. The beam reflected by the PBS 13 becomes converged light by the condenser lens 16 and enters the photodetector 17. The photodetector 17 is composed of, for example, a four-divided photodetector. The light beam incident on the photodetector 17 is photoelectrically converted into an electric signal and amplified. The amplified signal is equalized and binarized by the signal processing circuit 24. That is, the signal processing circuit 24 generates a code word and transmits it to the demodulation circuit 25. The demodulation circuit 25 demodulates the data word from the code word according to the demodulation tables shown in FIGS. 4A to 4D.

  FIG. 2 is a diagram illustrating an example of the modulation circuit 21 illustrated in FIG. The modulation circuit 21 includes a code table 211, a state register 212, a code connector 213, and a DSV (Digital sum value) controller 214.

  The code table 211 includes a modulation table shown in FIGS. 3A to 3E. 3A to 3E are diagrams illustrating an example of a modulation table for NRZI (non-return-to-zero-inverted recording) for modulating various data words into code words. As shown in FIGS. 3A-3E, the modulation table specifies the code word selected in state 0 and one of the next states 0, 1, 2 corresponding to each of the various data words. State information, next state information designating one of the code word selected in state 1 and the next state 0, 1, 2 and code word selected in state 2 and next state 0, 1, 2 Next state information designating one of the following is included. 4A to 4D are diagrams illustrating an example of a demodulation table for demodulating a data word from a code word modulated by the modulation table illustrated in FIGS. 3A to 3E.

  The state register 212 registers next state information corresponding to the selected code word and notifies the code table 211 as state information. The code connector 213 connects code words sequentially output from the code table 211. The DSV controller 214 controls the DSV of the connected codeword.

  Subsequently, the output of the test code by the optical disk apparatus shown in FIG. 1 will be described. An example of high-frequency occurrence control of the pattern “100000 000001” (so-called 11T pattern) by the host computer 40 using the modulation table shown in FIG. 3B and the demodulation table shown in FIG. 4C will be described.

  First, 11T is selected from the demodulation table shown in FIG. 4C. That is, the code word 100000 000001 is selected, and the data word 49h (h: hexadecimal) corresponding to the code word 100000 000001 is selected. Note that “z” in the demodulation table shown in FIG. 4C indicates a demodulation error.

  Next, referring to the data word 49h in the modulation table shown in FIG. 3B, the code word 100000 000001 corresponding to the data word 49h is selected. There are three types of code words corresponding to the data word 49h. That is, there are a code word corresponding to state 0, a code word corresponding to state 1, and a code word corresponding to state 2. A code word 100000 000001 is selected from these three types of code words, and a state 0 corresponding to the code word 100000 000001 is detected.

  Subsequently, a modulation source data word B 49h is defined. B is a codeword that satisfies both of the following (1) and (2).

(1) A code word associated with state information designating state 0 is selected as the next state (Next state).

(2) A code word including an odd number of bits 1 (an odd number of bit inversion locations) is selected.

  For example, as shown in FIG. 3B, the codeword 010001 000010 of state 1 corresponding to 62h is associated with state information in which the next state always specifies state 0, and includes three bits 1. Therefore, the modulation source data word 62h 49h can be selected.

  The main data including the repetitive pattern of the modulation source data word 62h 49h is modulated without being scrambled. That is, 62h 49h is modulated to the modulation pattern “010001 000010 100000 000001 010001 000010 100000 000001” by the modulation table. This modulation pattern is converted into a non-return-to-zero recording (NRZ) modulation pattern. That is, the modulation pattern is converted into the NRZ modulation pattern “011110 000011 000000 000001 100001 111100 111111 111110”. When this NRZ modulation pattern is divided into 4-bit units, a 4-bit unit pattern “0111 1000 0011 0000 0000 0001 1000 0111 1100 1111 1111 1110” is obtained. When this 4-bit unit pattern is expressed in HEX (hexadecimal), a code “78h 30h 01h 87h CFh FEh” is obtained. That is, when the main data including the repetition pattern of the modulation source data word 62h 49h is modulated without being scrambled, a test pattern including repetition of the code 7830 0187 CFFE is obtained. When “001” included in the code 7830 0187 cffe is expressed by 4 bits × 3 data, “0000 0000 0001” is obtained. Further, when “FFE” in the code 7830 0187 CFFE is expressed by 4 bits × 3, it becomes “1111 1111 1110”. When a test pattern including a repetitive pattern of “0000 0000 0001” and “1111 1111 1110” is recorded by NRZ, 11T space (001) and 11T mark (FFE) appear alternately as shown in FIG. If a pattern of only 11T space (001) is generated, the DSV is biased, which is not suitable for signal quality adjustment. As described above, a code having a high 11T appearance frequency can be recorded. In addition, since the test pattern includes patterns other than 11T, it is possible to relatively easily acquire the synchronous clock by the PLL.

  Here, the above-described scrambling will be described. The signal processing circuit of the optical disk apparatus shown in FIG. 1 scrambles main data including a code word during actual recording, and performs ECC (error correction code) encoding on the scrambled data. On the other hand, the signal processing circuit of the optical disk apparatus shown in FIG. 1 performs ECC encoding on the unscrambled data without scramble the main data including the code word at the time of test recording. That is, both actual recording and test recording can be realized by simply switching on / off the scramble between actual recording and test recording.

  With reference to the flowchart shown in FIG. 6, an example of the high-frequency occurrence control of the “100000 000001” pattern (so-called 11T pattern) by the host computer 40 described above is generalized and described below.

  First, a desired code word is selected from the demodulation tables shown in FIGS. 4A to 4D (ST1), and a data word A (A: two-digit hexadecimal number) corresponding to the selected code word is selected (ST2). .

  Next, the code word corresponding to the data word A is selected with reference to the data word A in the modulation table shown in FIGS. 3A to 3E. The desired code word is selected from the three types of code words corresponding to the data word A (ST3), and the state N (N = 0, 1, 2, 1) corresponding to the selected desired code word is selected. ) Is detected (ST4).

  Subsequently, a modulation source data word B A (B: a two-digit hexadecimal number) is defined (ST5). B is a codeword that satisfies both of the following (1) and (2).

(1) A code word associated with state information designating state N is selected as the next state (Next state).

(2) A code word including an odd number of bits 1 (an odd number of bit inversion locations) is selected.

  The main data including the repetitive pattern of the modulation source data word B A is modulated without being scrambled to generate a test pattern (ST6).

  As described above, a code having a high appearance frequency of a desired codeword can be recorded without using a dedicated circuit. Thereby, it is possible to reduce the trial writing data size and the recording learning time in the recording learning.

  Note that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention in the implementation stage. In addition, the embodiments may be appropriately combined as much as possible, and in that case, the combined effect can be obtained. Further, the above embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. For example, even if some constituent requirements are deleted from all the constituent requirements shown in the embodiment, the problem described in the column of the problem to be solved by the invention can be solved, and the effect described in the column of the effect of the invention Can be obtained as an invention.

1 is a block diagram showing a schematic configuration of an optical disc device (test code output device) according to an embodiment of the present invention. It is a figure which shows an example of the modulation circuit shown in FIG. It is a figure which shows an example of a modulation table. It is a figure which shows an example of a modulation table. It is a figure which shows an example of a modulation table. It is a figure which shows an example of a modulation table. It is a figure which shows an example of a modulation table. It is a figure which shows an example of a demodulation table. It is a figure which shows an example of a demodulation table. It is a figure which shows an example of a demodulation table. It is a figure which shows an example of a demodulation table. It is a figure for demonstrating the merit by 11T space and 11T mark appearing alternately. It is a flowchart which shows an example of a test code output.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Optical pick-up, 21 ... Modulation circuit, 22 ... Recording / reproduction control part, 23 ... Laser control circuit, 24 ... Signal processing circuit, 25 ... Demodulation circuit, 26 ... Actuator, 30 ... Focus / tracking control part, 40 ... Host computer 211 ... Code table 212 ... State register 213 ... Code connector 214 ... DSV controller

Claims (5)

A test code output method using a modulation table for modulating various data words into code words,
The modulation table is selected in state 1, which is a code word selected in state 0 corresponding to each of various data words, and next state information designating one of the next states 0, 1, and 2. Next state information for designating a code word and one of the next states 0, 1 and 2, and a code word selected in state 2 and the next designating one of the next states 0, 1 and 2 Including state information,
Selecting a data word A (A: two-digit hexadecimal number) corresponding to a desired code word from the demodulation table for demodulating the data word from the code word modulated by the modulation table;
From the modulation table, the state N (N = 0, 1, 2) of the desired code word corresponding to the data word A is detected,
From the modulation table, a code word associated with next state information designating the state N as a next state and including an odd number of bits 1 is detected,
Select data word B (B: two-digit hexadecimal number) corresponding to the detected code word,
Outputting a test code generated by modulating a test data word including a plurality of data words B A;
A test code output method characterized by that. A test code output method using a modulation table for modulating various data words into code words,
The modulation table is selected in state 1, which is a code word selected in state 0 corresponding to each of various data words, and next state information designating one of the next states 0, 1, and 2. Next state information for designating a code word and one of the next states 0, 1 and 2, and a code word selected in state 2 and the next designating one of the next states 0, 1 and 2 Including state information,
A data word 49h (h: hexadecimal) corresponding to a desired code word 100000 000001 is selected from the demodulation table for demodulating the data word from the code word modulated by the modulation table;
Detecting from the modulation table the state 0 of the desired code word corresponding to the data word 49h;
From the modulation table, a code word 010001 000010 which is a code word associated with next state information designating the state 0 as a next state and includes an odd number of bits 1 is detected.
Select a data word 62h (h: hexadecimal) corresponding to the detected code word 010001 000010,
Outputting a test code generated by modulating a test data word including a plurality of data words 62h 49h;
A test code output method characterized by that.   The test code output method according to claim 2, wherein the modulation table is a modulation table for non-return-to-zero-inverted recording (NRZI). A storage means for storing a modulation table for modulating various data words into code words, and a demodulation table for demodulating the data words from the code words modulated by the modulation table;
Output means for outputting a test code generated by modulating a test data word including a plurality of data words B A (A, B: two-digit hexadecimal numbers) generated based on the modulation table and the demodulation table;
With
The modulation table is selected in state 1, which is a code word selected in state 0 corresponding to each of various data words, and next state information designating one of the next states 0, 1, and 2. Next state information for designating a code word and one of the next states 0, 1 and 2, and a code word selected in state 2 and the next designating one of the next states 0, 1 and 2 Including state information,
The output means includes
From the demodulation table, select the data word A corresponding to the desired code word,
From the modulation table, the state N (N = 0, 1, 2) of the desired code word corresponding to the data word A is detected,
From the modulation table, a code word associated with next state information designating the state N as a next state and including an odd number of bits 1 is detected,
Selecting a data word B corresponding to the detected codeword;
Generating the data word B A;
A test code output device characterized by that.   5. The test code output device according to claim 4, further comprising scramble means for scramble a code word for actual recording and not scramble a code word for test recording.

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