Bus reversible orthogonal differential vector signaling codes

• US 10,003,424 B2
• Filed: 08/30/2016
• Issued: 06/19/2018
• Est. Priority Date: 07/17/2014
• Status: Active Grant

• Current Assignee: Kandou Labs, SA
• Original Assignee: Kandou Labs, SA
• Inventors: Ulrich, Roger, Shokrollahi, Amin
• Primary Examiner(s): Guarino, Rahel
• Application Number:
  US15/251,912
• Publication Number:
  US 20160373200A1
• Time in Patent Office: 658 Days
• CPC Class Codes: G06F 13/4282 on a serial bus, e.g. I2C bus, SPI bus on daisy chain buses G06F13/4247
• CPC Class Codes: G06F 17/10 Complex mathematical operations function generation by table look-up G06F1/03; evaluation of elementary functions by calculation G06F7/544
• CPC Class Codes: G06F 9/30036 Instructions to perform operations on packed data, e.g. vector, tile or matrix operations
• CPC Class Codes: H04B 3/50 Systems for transmission between fixed stations via two-conductor transmission lines H04B3/54 takes precedence
• CPC Class Codes: H04J 11/00 Orthogonal multiplex systems, e.g. using WALSH codesH04J13/00 takes precedence
• CPC Class Codes: H04L 1/0668 Orthogonal systems, e.g. using Alamouti codes
• CPC Class Codes: H04L 27/2602 Signal structure

Abstract

Properties and the construction method of Orthogonal Differential Vector Signaling Codes are disclosed which are tolerant of order-reversal, as may occur when physical routing of communications channel wires causes the bus signal order to be reversed. Operation using the described codes with such bus-reversed signals can avoid complete logical or physical reordering of received signals or other significant duplication of receiver resources.

Claims

1. A method comprising:

receiving a set of input bits and responsively generating a set of symbols of a codeword based on the set of input bits and a P-amenable orthogonal matrix, the P-amenable orthogonal matrix based on orthogonal generating matrix and a permutation matrix P; and

,

forming a set of permuted symbols using a multi-wire transmission bus, wherein the set of permuted symbols represents a wire permutation of the set of symbols of the codeword, the wire permutation based on the permutation matrix P, the permutation matrix P associated with the multi-wire transmission bus; and

transmitting the set of permuted symbols on the multi-wire transmission bus.

2. The method of claim 1, wherein the P-amenable orthogonal matrix represents a permutation of columns of the orthogonal generating matrix.

3. The method of claim 1, wherein the orthogonal generating matrix is represented by M:

4. The method of claim 1, wherein the orthogonal generating matrix is represented by M:

5. The method of claim 1, wherein the orthogonal generating matrix is represented by M:

6. The method of claim 1, wherein the permutation matrix P is a monomial matrix having a single ‘

1’

value in each column and in each row and ‘

0’

values elsewhere, each respective column associated with a respective symbol of the permuted set of symbols, wherein each respective column selects a respective symbol of an original set of symbols as the respective symbol of the permuted set of symbols, the selection based on a location of the ‘

1’

value in the respective column.

7. The method of claim 1, wherein the permutation matrix P is represented as:

8. The method of claim 1, wherein generating the codeword comprises weighting elements of each row of the P-amenable orthogonal matrix with a respective input, and forming an element-wise summation of the weighted rows of the P-amenable orthogonal matrix.

9. The method of claim 1, wherein each input bit has a value representing an antipodal weight, wherein each input has a value selected from a set of two values having equal magnitude and opposite sign.

10. The method of claim 1, wherein 5 input bits are encoded into 6 symbols of the codeword.

11. The method of claim 10, wherein the codeword has symbol values selected from a set [±

1, ±

⅓

].

12. The method of claim 1, wherein the orthogonal generating matrix is a Hadamard matrix H.

13. The method of claim 12, wherein the Hadamard matrix H is represented as:

14. The method of claim 1, wherein the P-Amenable orthogonal matrix is obtained by permuting columns of the orthogonal generating matrix.

15. The method of claim 1, wherein the codeword is part of an orthogonal differential vector signaling (ODVS) code.

16. The method of claim 1, further comprising:

receiving the set of permuted symbols via the multi-wire transmission bus; and

forming a set of output bits from the received set of permuted symbols using a set of comparators having input weights based on respective rows of the P-amenable orthogonal matrix, wherein the P-amenable orthogonal matrix is based on the orthogonal generating matrix and the permutation matrix P, the set of output bits corresponding to the set of input bits; and

,

outputting the set of output bits.

17. The method of claim 16, wherein forming the set of output bits comprises performing Boolean logic on outputs from the set of comparators.

18. The method of claim 17, wherein the Boolean logic comprises a logical reordering of the comparator outputs.

19. The method of claim 17, wherein the Boolean logic comprises a binary inversion of at least one of the comparator outputs.

20. The method of claim 16, wherein each comparator has a set of input weights selected from a respective row of a scaled version of the P-amendable orthogonal matrix, wherein a sum of positive entries in the respective row of the scaled version of the P-amendable orthogonal matrix is equal to one.