Methods and systems for high bandwidth communications interface
A pair of ground planes arranged in parallel, a dielectric medium disposed in between the pair of ground planes, and a set of at least four signal conductors disposed in the dielectric medium, the set of at least four signal conductors having (i) a first pair of signal conductors arranged proximate to a first ground plane of the pair of ground planes and (ii) a second pair of signal conductors arranged proximate to a second ground plane of the pair of ground planes, each signal conductor of the set of at least four signal conductors configured to carry a respective signal corresponding to a symbol of a codeword of a vector signaling code.
1. A method comprising
obtaining a plurality of signals via a plurality of signal conductors embedded in a dielectric medium, the plurality of signal conductors having pairs of equidistant signal conductors that are adjacent to respective ground planes of a pair of ground planes arranged in parallel;
generating a plurality of outputs, each output associated with a respective transmission mode of a plurality of transmission modes, wherein the plurality of outputs are formed based on comparisons between pair-wise combinations of signals of the obtained plurality of signals, wherein the pair-wise combinations of signals comprises (i) pair-wise combinations of signals obtained from pairs of horizontally-proximate signal conductors, (ii) pair-wise combinations of signals obtained from pairs of vertically-proximate signal conductors, and (iii) pair-wise combinations of signals obtained from pairs of diagonally-proximate signal conductors.
2. The method of claim 1 , wherein the plurality of signals are balanced.
3. The method of claim 1 , wherein the pair of ground planes arranged in parallel are connected by conductive vias.
4. The method of claim 1 , wherein the plurality of transmission modes are defined by an orthogonal matrix.
5. The method of claim 4 , wherein the orthogonal matrix is a Hadamard matrix of size four.
6. The method of claim 5 , wherein the plurality of signals correspond to codewords of a vector signaling code comprising all permutations of {+1, −⅓, −⅓, −⅓} and {−1, ⅓, ⅓, ⅓}.
7. The method of claim 1 , wherein the pairs of equidistant signal conductors have periodic horizontal offsets along a length of the dielectric medium.
8. An apparatus comprising
a plurality of signal conductors embedded in a dielectric medium, the plurality of signal conductors comprising pairs of equidistant signal conductors that are adjacent to respective ground planes of a pair of ground planes arranged in parallel, each signal conductor of the plurality of signal conductors carrying a respective signal of a plurality of signals;
a plurality of multi-input comparators (MICs) configured to generate a plurality of outputs, each MIC of the plurality of MICs connected to the plurality of signal conductors and associated with a respective transmission mode of a plurality of transmission modes, the plurality of MICs configured to generate the plurality of outputs based on comparisons between pair-wise combinations of signals of the plurality of signals, wherein the pair-wise combinations of signals comprises (i) pair-wise combinations of signals obtained from a pair of horizontally-proximate signal conductors, (ii) pair-wise combinations of signals obtained from a pair of vertically-proximate signal conductors, and (iii) pair-wise combinations of signals obtained from a pair of diagonally-proximate signal conductors.
9. The apparatus of claim 8 , wherein the plurality of signals are balanced.
10. The apparatus of claim 8 , wherein the pair of ground planes arranged in parallel are connected via conductive vias.
11. The apparatus of claim 8 , wherein the plurality of transmission modes are defined by an orthogonal matrix.
12. The apparatus of claim 11 , wherein the orthogonal matrix is a Hadamard matrix of size four.
13. The apparatus of claim 12 , wherein the plurality of signals correspond to codewords of a vector signaling code comprising all permutations of {+1, −⅓, −⅓, −⅓} and {−1, ⅓, ⅓, ⅓}.
14. The apparatus of claim 8 , wherein the pairs of equidistant signal conductors have periodic horizontal offsets along a length of the dielectric medium.
15. The apparatus of claim 8 , wherein the plurality of signal conductors are arranged in a square in the dielectric medium.