Method and apparatus for implementing codes with maximum transition run length

• US 5,731,768 A
• Filed: 01/31/1996
• Issued: 03/24/1998
• Est. Priority Date: 01/31/1996
• Status: Expired due to Term

• Current Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Original Assignee: Seagate Technology plc (Seagate Technology Holdings Plc)
• Inventors: Tsang, Kinhing P.
• Primary Examiner(s): Young, Brian K.
• Application Number:
  US08/594,987
• Time in Patent Office: 783 Days
• Field of Search: 341/59, 341/58, 341/50, 341/93, 341/94, 341/82
• US Class Current: 341/59
• CPC Class Codes: G06T 9/005 Statistical coding, e.g. Huffman, run length coding
• CPC Class Codes: G11B 20/1426 conversion to or from block codes or representations thereof
• CPC Class Codes: H03M 5/145 Conversion to or from block codes or representations thereof

Abstract

Encoding and decoding systems for data blocks based on forming corresponding code blocks having a maximum number of successive repetitions of a first symbol and a maximum number of successive repetitions of a second symbol, and having code blocks which can represent plural different ones of said data blocks unambiguously by having further code blocks aid in distinguishing data block is being represented.

Claims

1. An apparatus for encoding selected data blocks having a selected data number of ordered symbols therein into corresponding code blocks having a selected code number of ordered symbols therein with said code number being greater than said data number, the apparatus comprising:

a encoding receiver for receiving said data blocks; and

an encoder coupled to said encoding receiver for providing a corresponding said code block for each said data block, such that (a) each said code block and any concatenations of said code blocks are without more than a preselected first symbol number of successive repetitions of a first symbol throughout, and without more than a preselected second symbol number of successive repetitions of a second symbol throughout, and (b) any of said code blocks, there are provided for each of plural different ones of said data blocks, are also provided, in representing a said data block, in a concatenation of said code blocks such that such a said plural representation code block together with at least one other said code block in that said concatenation therewith are sufficient to determine which of said different ones of said data blocks representable by said plural representation code block is being represented.

2. The apparatus of claim 1 wherein each code block is represented with binary number system symbols such that said first symbol is a "0" and said second is a "1".

3. The apparatus of claim 1 wherein said first symbol number equals nine.

4. The apparatus of claim 1 wherein said second symbol number equals two.

5. The apparatus of claim 1 wherein said selected data number equals five, and wherein said selected code number equals six.

6. The apparatus of claim 1 wherein said selected data number equals six, and wherein said selected code number equals seven.

7. The apparatus of claim 1 whereto said encoder is based on a finite state machine formed in a microprocessor.

8. The apparatus of claim 2 wherein said first symbol number equals nine.

9. The apparatus of claim 2 wherein said second symbol number equals two.

10. The apparatus of claim 2 wherein said selected data number equals five, and wherein said selected code number equals six.

11. The apparatus of claim 2 wherein said selected data number equals six, and wherein said selected code number equals seven.

12. The apparatus of claim 2 wherein said encoder is based on a finite state machine formed in a microprocessor.

13. The apparatus of claim 12 wherein said code blocks are divided into classes of mutually exclusive code blocks with a different one of such classes being assigned to transitions from each state to another state in response to receipt of a corresponding data block to thereby arise as corresponding encoder outputs as a result of such transitions.

14. The apparatus of claim 13 wherein said classes are each divided into subclasses based on that next state to which a said transition leads with code blocks from each class being permitted to be in plural ones of those said subclasses formed from that class.

15. The apparatus of claim 14 further comprising a decoding receiver for receiving code blocks encoding corresponding said data blocks in that manner followed by said encoder so as to permit storing successive code blocks received therein concurrently, and a decoder for obtaining data blocks corresponding to said received code blocks and corresponding next states therefor.

16. An apparatus for decoding selected code blocks having a selected code number of ordered symbols therein into corresponding data blocks having a selected data number of ordered symbols therein with said code number being greater than said data number, the apparatus comprising:

a decoding receiver for receiving said code blocks; and

an decoder coupled to said decoding receiver for providing a corresponding said data block for each said code block, wherein (a) each said code block and any concatenations of said code blocks are without more than a preselected first symbol number of successive repetitions of a first symbol throughout, and without more than a preselected second symbol number of successive repetitions of a second symbol throughout, and (b) any of said code blocks, that are provided for each of plural different ones of said data blocks, are also provided, in representing a said data block, in a concatenation of said code blocks such that such a said plural representation code block together with at least one other said code block in that said concatenation therewith are sufficient to determine which of said different ones of said data blocks representable by said plural representation code block is being represented.

17. The apparatus of claim 16 wherein said first symbol number equals nine and said second symbol number equals two.

18. The apparatus of claim 16 wherein the decoding receiver comprises:

a first register, having an input for receiving code blocks, and an output for providing received code blocks;

a second register, having an input for receiving code blocks, the input coupled to the output of the first register, the second register also having an output from providing received code blocks, the output of the second register coupled to the decoder;

a state determiner, having an input coupled to the output of the first register, and an output coupled to the decoder, the state determiner for producing a value at its output representing the next state of the decoder corresponding to the code block at the output of the second register.

19. The apparatus of claim 18 wherein the decoding receiver further comprises:

a delay register having an input coupled to the output of the state determiner and an output coupled to the decoder, the output of the delay register for providing a current state of the decoder corresponding to the code block at the output of the second register.