Symbol encoding for tolerance to single byte errors

• US 8,607,117 B2
• Filed: 11/26/2012
• Issued: 12/10/2013
• Est. Priority Date: 11/18/2003
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Whitby-Strevens, Colin, Hauck, Jerrold Von
• Primary Examiner(s): ABRAHAM, ESAW T
• Application Number:
  US13/685,586
• Publication Number:
  US 20130151910A1
• Time in Patent Office: 379 Days
• Field of Search: 714/752, 714/786, 714/799
• US Class Current: 714/752
• CPC Class Codes: G06F 11/10 Adding special bits or symbols to the coded information, e.g. parity check, casting out 9's or 11's
• CPC Class Codes: H03M 13/31 combining coding for error detection or correction and efficient use of the spectrum without error detection or correction H03M5/14 , H03M5/145
• CPC Class Codes: H03M 5/145 Conversion to or from block codes or representations thereof

Abstract

The present invention provides a method that protects symbol types by characterizing symbols as one of two types—DATA or NON_DATA, generating a symbol characterization bit, placing the symbol characterization bit at both ends of the symbol, and transmitting the symbol with the symbol characterization bits at both ends. Thus, a single byte error may affect a type bit in two consecutive symbols, and will affect one or the other of the type bits in a single symbol, but cannot affect both type bits in a single symbol.

Claims

1. An apparatus comprising:

a processor; and

a non-transitory computer readable medium comprising one or more instructions, the instructions configured to, when executed by the processor, cause the apparatus to;

generate data based at least in part on a portion of a first symbol and a portion of a second symbol, wherein the portion of the first symbol is indicative of a first symbol type and the portion of the second symbol is indicative of a second symbol type; and

determine when the generated data is corrupted, and when the generated data is corrupted;

determine if the first symbol is valid, based at least in part on the first symbol type; and

determine if the second symbol is valid, based at least in part on the second symbol type.

2. The apparatus of claim 1, wherein each of the first and second symbols has multiple portions indicative of symbol type.

3. The apparatus of claim 2, wherein the multiple portions are at opposite ends of each symbol.

4. The apparatus of claim 1, additionally comprising logic configured to correct corrupted data if at least one of the first and second symbols is determined to be valid.

5. The apparatus of claim 4, wherein the correction of corrupted data comprises replacement of the corrupted data if at least one of the first and second symbols is determined not to be valid.

6. A method of recovering received data, the method comprising:

recovering a first symbol and second symbol from a plurality of bytes, where the first symbol spans a first byte and a second byte, and where the second symbol spans the second byte and a third byte;

identifying a symbol type for each of the first recovered symbol, and the second recovered symbol;

detecting that one or more bytes of the recovered first symbol and second symbol are corrupted; and

restoring at least one of the first and second symbols based on the identified symbol types.

7. The method of claim 6, wherein the first, second, and third bytes are consecutively ordered.

8. The method of claim 7, wherein the first and second symbols are consecutively ordered.

9. The method of claim 6, wherein the symbol types of the recovered first and second symbol are identified using at least a first bit and/or last bit of the first and second recovered symbols, respectively.

10. The method of claim 6, wherein the restoring of at least one of the first and second symbols comprises decoding the one or more bytes of corrupted data when at least one of the first or second symbols are not valid.

11. The method of claim 10, wherein the restoring of at least one of the first and second symbols comprises replacing the one or more bytes of corrupted data when at least one of the first or second symbols are not valid.

12. The method of claim 6, wherein the first and second symbols each comprise at least multiple data portions indicative of a symbol type.

13. An apparatus comprising:

a processor; and

logic in data communication with the processor, the logic configured to;

recover a first symbol and second symbol from a plurality of bytes;

identify first and second symbol types for the first and second recovered symbols, respectively;

determine that one or more bytes of the first and second symbols are corrupted; and

restore at least one of the first and second symbols based on the identified first and second symbol types.

14. The apparatus of claim 13, wherein the first and second symbol types are determined via one or more bit portions of the recovered first and second symbols, respectively.

15. The apparatus of claim 14, wherein the content of the one or more bit portions used to identify the first and second symbol types are repeated at the beginning and end of the first and second recovered symbols, respectively.

16. The apparatus of claim 13, wherein the logic is further configured to determine that the first and second recovered symbols are valid symbols based at least in part on the identified symbol types.

17. The apparatus of claim 16, wherein the logic configured to restore at least one of the first and second symbols is further configured to replace the one or more bytes of corrupted data when at least one of the first or second symbols are invalid.

18. The apparatus of claim 16, wherein the logic configured to restore at least one of the first and second symbols is further configured to decode the one or more bytes of corrupted data when at least one of the first or second symbols are not valid.

19. The apparatus of claim 13, wherein:

the first symbol spans at least a portion of a first byte and at least a portion of a second byte; and

the second symbol includes at least a portion of the second byte and at least a portion of a third byte.

20. The apparatus of claim 19, wherein the first and second symbols are consecutively ordered.

21. The apparatus of claim 13, wherein the first and second symbol types comprise the same symbol type.