RECORDING MODULATION CIRCUIT, RECORDING MODULATION METHOD AND OPTICAL DISK APPARATUS
After a transfer error detection circuit detects a transfer error that transfer data from a memory controller to a recording modulation circuit is delayed for a recording clock process, the number of transfer errors is counted in units of sync frame in a transfer error count circuit. When the number of transfer errors is n times (n: positive integer) or less, the modulation and recording operation are continued as it is and the NRZI output operation is performed from the correct position while applying a sync, and when the number of transfer errors is n times or larger, the recording operation is interrupted and the re-recording is performed from the interrupted location thereafter.
1 . A recording modulation circuit for performing modulation in accordance with a modulation scheme for modulating a data word of i bits (i is a positive integer) to a code word of j bits (j is a positive integer) and outputting a signal obtained by converting an obtained modulation output data to code data and a write gate indicating a recording range of the modulation output data on an optical disk in an optical disk apparatus for recording digital data on an optical disk by light irradiation, the recording modulation circuit comprising:
means for detecting a transfer error on the data word read from a memory in the optical disk apparatus and input to the recording modulation circuit by a memory controller of the optical disk apparatus,
wherein, when the transfer error is detected, dummy data is output and a recording modulation operation is continued without being interrupted, and if the detection of the transfer error is stopped thereafter, the output of the modulation output data is resumed from a next sync frame.
2 . The recording modulation circuit according to claim 1 ,
wherein a number of times of detection of the transfer error is counted for every sync frame, if the counted number of transfer errors is smaller than n (n: positive integer), the recording modulation operation is continued without being interrupted, and if the counted number of transfer errors is n or larger, the write gate is invalidated so that the modulation output data is not output.
3 . The recording modulation circuit according to claim 2 ,
wherein, when the counted number of transfer errors is n or larger and the write gate is invalidated, if the detection of the transfer error is stopped thereafter, the invalidated write gate is validated, and the output of the modulation output data is resumed.
4 . The recording modulation circuit according to claim 2 ,
wherein, when the counted number of transfer errors is n or larger, the dummy data equivalent to an ECC block where the transfer error is detected is output with the write gate being validated, and if the detection of the transfer error is stopped thereafter, the output of the modulation output data is resumed from a head of a next ECC block.
5 . The recording modulation circuit according to claim 1 ,
wherein the dummy data is data of a unique array identifiable from a user data portion and a sync code portion in the modulation output data.
6 . The recording modulation circuit according to claim 5 ,
wherein the dummy data is NRZI code data complying with the modulation scheme in an optical disk to be a recording target of the recording modulation circuit, and is data with an array in which DSV becomes 0.
7 . The recording modulation circuit according to claim 6 ,
wherein the dummy data is data of a repetitive pattern with a channel bit length not corresponding to a range of a channel bit length used in the user data portion and the sync code portion in a format of code data in the optical disk to be the recording target of the recording modulation circuit, or the dummy data is data of a repetitive pattern with a channel bit length equal to that used in a guard portion.
8 . The recording modulation circuit according to claim 2 , further comprising:
means for holding the value n,
wherein the value n can be changed by setting from outside.
9 . The recording modulation circuit according to claim 2 ,
wherein the number of times of detection of the transfer error is counted for every sector.
10 . The recording modulation circuit according to claim 9 ,
wherein whether the number of times of detection of the transfer error is counted for every sync frame or for every sector can be switched by setting from outside.
11 . A recording modulation circuit for performing modulation in accordance with a modulation scheme for modulating a data word of i bits (i is a positive integer) to a code word of j bits (j is a positive integer) and outputting a signal obtained by converting an obtained modulation output data to code data and a write gate indicating a recording range of the modulation output data on an optical disk in an optical disk apparatus for recording digital data on an optical disk by light irradiation, the recording modulation circuit comprising:
means for detecting a transfer error on the data word read from a memory in the optical disk apparatus and input to the recording modulation circuit by a memory controller of the optical disk apparatus,
wherein, when the transfer error is detected, the write gate is invalidated so that the modulation output data is not output, and if the detection of the transfer error is stopped thereafter, the invalidated write gate is validated, and output of the modulation output data is resumed from a next sync frame.
12 . The recording modulation circuit according to claim 1 ,
wherein whether a function of recording modulation operation when the transfer error is detected is validated or not can be switched by setting from outside.
13 . An optical disk apparatus for recording digital data on an optical disk by light irradiation, the optical disk apparatus comprising:
a recording modulation circuit for performing modulation in accordance with a modulation scheme for modulating a data word of i bits (i is a positive integer) to a code word of j bits (j is a positive integer) and outputting a signal obtained by converting an obtained modulation output data to code data and a write gate indicating a recording range of the modulation output data on an optical disk; and
a memory controller for reading out the data word from a memory and outputting the data word to the recording modulation circuit,
wherein the recording modulation circuit includes means for detecting transfer error of the data word from the memory controller to the recording modulation circuit, and
when the transfer error is detected, dummy data is output and a recording modulation operation is continued without being interrupted, and if the detection of the transfer error is stopped thereafter, output of the modulation output data is resumed.
14 . An optical disk apparatus for recording digital data on an optical disk by light irradiation, the optical disk apparatus comprising:
a recording modulation circuit for performing modulation in accordance with a modulation scheme for modulating a data word of i bits (i is a positive integer) to a code word of j bits (j is a positive integer) and outputting a signal obtained by converting an obtained modulation output data to code data and a write gate indicating a recording range of the modulation output data on an optical disk; and
a memory controller for reading out the data word from a memory and outputting the data word to the recording modulation circuit,
wherein the recording modulation circuit includes means for detecting transfer error of the data word from the memory controller to the recording modulation circuit, and
when the transfer error is detected, the write gate is invalidated so that the modulation output data is not output, and if the detection of the transfer error is stopped thereafter, the invalidated write gate is validated, and output of the modulation output data is resumed from a next sync frame.
15 . A recording modulation method in an optical disk apparatus comprising: a recording modulation circuit for performing modulation in accordance with a modulation scheme for modulating a data word of i bits (i is a positive integer) to a code word of j bits (j is a positive integer) and outputting a signal obtained by converting an obtained modulation output data to code data and a write gate indicating a recording range of the modulation output data on an optical disk; and
a memory controller for reading out the data word from a memory and outputting the data word to the recording modulation circuit,
wherein the optical disk apparatus executes the steps of:
detecting a transfer error of the data word from the memory controller to the recording modulation circuit;
outputting dummy data from the recording modulation circuit and continuing a recording modulation operation without interrupting when the transfer error is detected; and
resuming the output of the modulation output data from the recording modulation circuit from a next sync frame if the detection of the transfer error is stopped thereafter.
16 . A recording modulation method in an optical disk apparatus comprising: a recording modulation circuit for performing modulation in accordance with a modulation scheme for modulating a data word of i bits (i is a positive integer) to a code word of j bits (j is a positive integer) and outputting a signal obtained by converting an obtained modulation output data to code data and a write gate indicating a recording range of the modulation output data on an optical disk; and
a memory controller for reading out the data word from a memory and outputting the data word to the recording modulation circuit,
wherein the optical disk apparatus executes the steps of:
detecting a transfer error of the data word from the memory controller to the recording modulation circuit;
invalidating the write gate so that the modulation output data is not output from the recording modulation circuit when the transfer error is detected, and
validating the invalidated write gate if the detection of the transfer error is stopped thereafter, and resuming the output of the modulation output data from a next sync frame.
17 . An optical disk on which digital data is recorded by light irradiation,
wherein, by an optical disk apparatus which records the digital data on the optical disk, the optical disk apparatus including: a recording modulation circuit for performing modulation in accordance with a modulation scheme for modulating a data word of i bits (i is a positive integer) to a code word of j bits (j is a positive integer) and outputting a signal obtained by converting an obtained modulation output data to code data and a write gate indicating a recording range of the modulation output data on an optical disk; and a memory controller for reading out the data word from a memory and outputting the data word to the recording modulation circuit,
dummy data is recorded when transfer error of the data word from the memory controller to the recording modulation circuit is detected in the recording modulation circuit, and recording of the modulation output data is resumed if the detection of the transfer error is stopped thereafter.
18 . An optical disk apparatus for recording digital data on an optical disk by light irradiation, the optical disk apparatus comprising:
a recording modulation circuit for performing modulation in accordance with a modulation scheme for modulating a data word of i bits (i is a positive integer) to a code word of j bits (j is a positive integer) and outputting a signal obtained by converting an obtained modulation output data to code data and a write gate indicating a recording range of the modulation output data on an optical disk;
a memory configuring an error correction block in which a parity is added to data and temporarily storing the same; and
a memory controller for controlling generation of the error correction block, reading out the error correction block from the memory and outputting the error correction block to the recording modulation circuit,
wherein, when generation of the error correction block is delayed for generation of the modulation output data output in synchronization with a recording clock in the recording modulation circuit due to that processes of the memory controller are occupied,
the recording modulation circuit continues recording modulation operation without interrupting if delay time of the output of the error correction block from the memory controller is within a range in which a burst error correction is possible at a time of reproduction of the optical disk.
19 . An optical disk recording method in an optical disk apparatus, the optical disk apparatus comprising:
a recording modulation circuit for performing modulation in accordance with a modulation scheme for modulating a data word of i bits (i is a positive integer) to a code word of j bits (j is a positive integer) and outputting obtained modulation output data so as to record the same on an optical disk;
a memory configuring an error correction block in which a parity is added to data and temporarily storing the same; and
a memory controller for controlling generation of the error correction block, reading out the error correction block from the memory and outputting the error correction block to the recording modulation circuit,
wherein, when generation of the error correction block is delayed for generation of the modulation output data output in synchronization with a recording clock in the recording modulation circuit due to that processes of the memory controller are occupied,
the recording modulation circuit continues recording modulation operation without interrupting if delay time of the output of the error correction block from the memory controller is within a range in which a burst error correction is possible at a time of reproduction of the optical disk.
20 . The recording modulation circuit according to claim 11 ,
wherein whether a function of recording modulation operation when the transfer error is detected is validated or not can be switched by setting from outside.