US 5,991,911 A · Concurrent generation of ECC error syndromes and CRC validation syndromes in a DVD storage device

Abstract

A compact disk (CD) and digital video disk (DVD) error correction system is disclosed which generates a CRC validation syndrome on-the-fly while correcting the CD/DVD product code, thereby reducing the overall access latency as compared to the prior art. For the DVD product code, which comprises multiple data sectors with separate CRC symbols appended to each data sector, a buffer used for C1 and C2 encoding/decoding in CD mode is used to store partial data and error CRC syndromes for each data sector. During the vertical (P) and horizontal (Q) passes over the DVD product code, data and error CRC syndrome registers are loaded with the appropriate partial CRC syndromes depending on the current data symbol being processed by a P/Q decoder. After processing each data sector, the data and error CRC syndromes for each data sector are combined and compared to a constant to determine whether the corrections to the data sector are valid and complete. The data and error CRC syndromes are adjusted during the P and Q passes to account for offsets in the CRC codeword symbols. For example, when processing a vertical (i.e., P) codeword, it is necessary to adjust the error CRC syndromes by one row of data symbols for each vertical symbol processed. This is carried out by using a special multiplier circuit which multiplies the data and error CRC syndromes by x.sup.k MODG(x) where k is the offset (e.g., one row of symbols) and G(x) is the CRC generator polynomial.

Claims18

Dependent claims

An error correction processor for correcting errors in binary data read from a disk storage medium, wherein the binary data comprises a plurality of intersecting ECC codewords of a multi-dimensional codeword, the multi-dimensional codeword comprising ECC redundancy symbols, validation redundancy symbols, and a plurality of data sectors, the error correction processor comprising:

(a) a data buffer for storing the ECC codewords read from the disk storage medium;
(b) a syndrome buffer for storing a plurality of intermediate values for use in generating a validation syndrome for each data sector;
(c) an ECC decoder for generating error syndromes in response to an ECC codeword stored in the data buffer, the error syndromes for correcting errors in the ECC codeword;
and
(d) an error correction validator for generating the validation syndromes in response to the validation redundancy symbols, the validation syndromes for verifying corrections made to the ECC codeword by the ECC decoder.

2 more elements

(a) a data buffer for storing the ECC codewords read from the disk storage medium;
(b) a syndrome buffer for storing a plurality of intermediate values for use in generating validation syndromes for each data sector;
(c) an ECC decoder for generating error syndromes in response to an ECC codeword stored in the data buffer, the error syndromes for correcting errors in the ECC codeword;
and
(d) an error correction validator for generating the validation syndromes in response to the validation redundancy symbols, the validation syndromes for verifying corrections made to the ECC codeword by the ECC decoder, the error correction validator comprising:
(i) a data validation register connected to receive one of a plurality of data validation values stored in the syndrome buffer corresponding to the plurality of data sectors;
(ii) an error validation register connected to receive one of a plurality of error validation values stored in the syndrome buffer corresponding to the plurality of data sectors;
(iii) a validation syndrome generator for combining a data validation value with a corresponding error validation value to generate one of the validation syndromes;
and
(iv) a comparator for comparing the validation syndrome to a predetermined value to determine if the errors made by the ECC decoder are valid and complete.

7 more elements

Dependencies are inferred from the claim text.

Concurrent generation of ECC error syndromes and CRC validation syndromes in a DVD storage device

Life of this patent

Concurrent generation of ECC error syndromes and CRC validation syndromes in a DVD storage device

Life of this patent

Abstract

Claims18