KR0162605B1 - Common circuit of rs decode syndrome generator for digital vcr system - Google Patents

Abstract

1. The technical field to which the invention described in the claims belongs:

In the digital VCR system, the present invention relates to an RS decoder symptom generator sharing circuit for inner code and sub code.

2. The technical problem the invention is trying to solve:

Provided is a circuit for sharing a syndrome generator in error correction of an inner code or subcode in error correction of a received data in a digital VCR or digital camcorder.

3. Summary of the Solution of the Invention:

In the digital VLC system, the RS decoder syndrome generator sharing circuit of the inner code and the sub code generates a syndrome S0 by using the following formula to calculate α ¹ = 1 at the time of the sub code and the inter code with the received data. first means, as inputs the received data at the time of the subcode GF (2 ⁴⁾ of α ^1, α ^2, α select the ^three values α ^1, α ^2, a is GF (2 ⁸⁾ when inner code α ³ The second means for generating syndromes S1 to S3 by selecting the value multiplied by the following formula, and α ⁴ , α ⁵ , α ⁶ , of GF (2 ⁸ ) only when inner code is input as the received data. The α ⁷ value is configured as third means for generating syndromes S4 to S7 using the following formula.

formula

S _j = r (α ^j ) = r ₀ + r ₁ α ^j + r ₂ (α ^j ) ² +. , r _n-1 (α ^j ) ^n-1

Where S _j = syndrome (j = 0-2t-1), r (x): reception data (x = α ^{0 -} α ^2t-1 )

4. Important uses of the invention:

Used in error correction techniques in digital VCRs or digital camcorders.

Description

RS decoder syndrome generator sharing circuit of inner code and sub code in digital V system

1 to 3 show a syndrome sharing generation circuit according to the present invention.

The present invention relates to a syndrome generator among functions of an RS (Reed Solomon) decoder having a function of correcting an error of data received from a digital VCR or a digital camcorder, and particularly an audio / video inner code among a plurality of codes to be decoded. The present invention relates to a syndrome sharing generating circuit for generating syndromes through a single circuit of a syndrome generator of an RS decoder, each of which is performed during error correction of an inner code and a sub code.

The SPEC specification in the Error Correction Code (ECC) technology of digital VCRs is as follows.

Video:

1) Outer Code:

Code Length: RS (149.138) GF (2 ⁸ )

-FGP: X ⁸ + X ⁴ + X ³ + X ² + 1

-CGP: (X + 1) (X + α) --- (X + α ¹⁰ )

Code Configuration: Video Data (135) + Video Aux (3) + Outer Parity (11)

2) Inner Code:

Code Length: RS (85.77) GF (2 ⁸ )

-FGP: X ⁸ + X ⁴ + X ³ + X ² + 1

-CGP: (X + 1) (X + α) --- (X + α ⁷ )

Code Structure: Video Data or Outer Parity (77) + Inner Parity (8)

Audio:

1) Outer Code:

Code Length: RS (14.9) GF (2 ⁸ )

-FGP: X ⁸ + X ⁴ + X ³ + X ² + 1

-CGP: (X + 1) (X + α) --- (X + α ⁴ )

Code composition: Audio Aux or Data (9) + Outer Parity (5)

2) Inner Code:

Code Length: RS (85.77) GF (2 ⁸ )

-FGP: X ⁸ + X ⁴ + X ³ + X ² +1

-CGP: (X + 1) (X + α) ---- (X + α ⁷ )

Code Configuration: Video Aux (5) Data (72) + Inner Parity (8) or Outer Parity (77) + Inner Parity (8)

ID:

Code Length: BCH (12.8) GF (2 ⁴ )

-FGP: X ⁴ + X + 1

-CGP: X ⁴ + X + 1

Subcode:

Code Length: RS (14.10) GF (2 ⁴ )

-FGP: X ⁴ + X + 1

-CGP: (X + 1) (X + α) (X + α ² ) (X + α ³ )

It is the RS decoder that corrects the errors according to these ECC specifications. Among the functions of the RS decoder is a syndrome generator for generating syndromes. The syndrome generator is composed of error correcting of audio / video inner code and error correcting of audio / video sub code among a plurality of codes to be decoded, respectively. Each of these error-correcting configurations has a problem in circuit design, and has a burden of increasing the amount of circuits in the design.

Accordingly, it is an object of the present invention to provide a circuit for sharing a syndrome generator in error correction of an inner code or subcode of error reception of received data in a digital VCR or digital camcorder.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

In this specification, a syndrome refers to a value calculated when the roots of the generated polynomial are substituted into the generated polynomial of the received data. If the received data is a code word, all syndromes are zero. If an error occurs and the received data is not a codeword, the syndrome is not zero. Therefore, the RS decoder calculates the value and position of the error based on these syndromes.

The syndrome generator sharing circuit of the present invention is configured together in three forms, as shown in FIGS. 1, 2 and 3. 1 is a circuit for generating syndrome SO, which is composed of a multiplier 2, a multiplexer 4, and latches 6 and 8. As shown in FIG. 2 is a circuit for generating syndromes S1 to S3 and includes an adder 12, a multiplexer 14, latches 16 and 18, multipliers 20 and 22 and a multiplexer 24. As shown in FIG. 3 includes a multiplier 32, a multiplexer 34, latches 36 and 38, and a multiplier 40. As shown in FIG.

1 and 2 are used for both subcode and inner code, and FIG. 3 is used only for inner code. The multiplier of the first turn α ⁰ (α ⁰ = 1) generates a syndrome SO as the abbreviation, FIG. 2 in accordance with the selection signal sub-code of the multiplexer 24. If the Subcode signal 1 of the generator polynomial The data obtained by multiplying α ¹ , α ² , α ³ of the root GF (2 ⁴ ) (that is, the output of the multiplier 20) is selected (at the time of subcode decoding). When the subcode signal is 0, the data obtained by multiplying α ¹ , α ² , α ³ of the root GF (2 ⁸ ) of the generated polynomial (that is, the output of the multiplier 22) is selected (when encoding the inner code). FIG. 3 outputs syndromes S4 to S7 using values multiplied by α ⁴ , α ⁵ , α ⁶ , α ⁷ of the root GF (2 ⁸ ) of the generated polynomial in a form used only for inner code decoding. In FIG. 1, FIG. 2 and FIG. 3, the start signal applied to the selection terminal S of the multiplexers 4, 14 and 34 and the Oclk clock applied to the clock terminal of the latches 8, 18 and 38 are inner. It depends on the code and subcode.

In the RS code, syndrome is used to determine whether there is an error. If each syndrome is 0, there is no error. If the syndrome is output as a non-zero value, an error occurs. The number of syndromes generated in an RS code having t error correction capabilities is 2t. The syndrome is a result obtained by substituting the reception data (the input data IN into the roots α ⁰ , α ¹ , and α ^2t-1 of the generated polynomial).

GF (2 ⁸ ) = {α ⁰ , α ¹ , α ² ,... , α ²⁵³ , α ²⁵⁴ } where each symbol is 8-bit data

That is, syndrome Sj is calculated | required by the following formula.

Sj = r (α ^j ) = r ₀ + r ₁ α ^j + r ₂ (α ^j ) ² +. , r _n-1 (α ^j ) ^n-1

Where S _j = syndrome (j = 0 to 2t-1), r (x): reception data (x = α ^{0 to} α ^2t-1 )

The RS code lengths used for inner codes and subcodes in digital VCRs and digital camcorders are RS (85,77), RS (14,10) (GF (2 ⁸ ), GF (2 ⁴ ), respectively, as described in the above specification. ))to be. At this time, inner code RS (85,77) has t = 4, sub code RS (14, 10) has t = 2 error correction capabilities. Therefore, the inner code is a circuit that generates syndrome using two circuits having eight syndromes S0 to S7 using one circuit.

1, 2, and 3 together, all circuits generating syndromes S0 to S7 are used for inner codes, while only circuits generating S0 to S3 are used for subcodes. Referring to FIG. 1, the multiplier is omitted because α ⁰ is both 1 in RS (85, 77) and RS (14, 10). 3 is used only for inner code.

After all the necessary shared design of the second road on, since the value of α ^1, α ^2, α ³ when α ^1, α ^2, α ³ of the value and the sub-code of an inter mode, when are different from each other, the multiplexer 24 To select it. In other words, in the inner code, blocks of FIGS. 1, 2, and 3 are selected and used to generate syndromes S0 to S7 through multiplication of α ^{0 to} α ¹¹ . However, in the sub-code, the block shapes of FIG. 1 and FIG. 2 are selected and used to generate syndromes S0 to S3 through the multiplication of α ⁰ to α ³ .

In FIG. 2, when the subcode signal is 1 (when subcoded), if α ¹ , α ² , α ³ of GF (2 ⁴ ) is multiplied by the multiplier 20 and the subcode signal is 0 (inner code) H) Select data in which α ¹ , α ² , α ³ of GF (2 ⁸ ) is multiplied by multiplier 22.

As described above, the present invention has the effect of greatly reducing the amount of circuits in circuit design by sharing the syndrome generators of the inner code and the sub code which are conventionally performed in one circuit.

Claims (1)

In an RS coder syndrome generator sharing circuit of an inner code and a sub code in a digital VLC system, a syndrome S0 is generated by using a calculation equation to generate α ¹ = 1 at sub code and inter code with received data. No. when the sub-code by 1 and means, inputting the received data GF (2 ⁴⁾ of the α ^1, α ^2, α ^3, select a value to α ^1, α ^2, of, the GF (2 ⁸⁾ when the inner code α the second means and, GF (2 ⁸⁾ only at the inner code of the received data as an input to a ³ by using the calculating formula to select the multiplied value generating a syndrome S1~S3 ⁴ α, ⁵ α ,, α ^6, the syndrome generator circuit shared by the formula of an α value to ⁷ characterized in that it consists of a third means for generating a syndrome S4~S7. formula S _j = r (α ^j ) = r ₀ + r ₁ α ^j + r ₂ (α ^j ) ² +. , r _n-1 (α ^j ) ^n-1 Where S _j = syndrome (j = 0-2t-1), r (x): reception data (x = α ^{0 -} α ^2t-1 )