N-phase signal transition alignment

1. A data transfer method, comprising:

determining differences between each pair of consecutive symbols in a plurality of symbols to be transmitted on three or more connectors, wherein the differences relate to signaling states of the three or more connectors;

estimating a duration of a transition interval at a symbol boundary between the pair of consecutive symbols based on the differences; and

modifying operation of one or more drivers of the three or more connectors to reduce the duration of the transition interval when the duration of the transition interval is estimated to exceed a threshold period,

wherein modifying the operation of the one or more drivers comprises:

delaying or advancing an initiation of a state transition on at least one connector when the duration of the transition interval is estimated to exceed the threshold period; and

refraining from delaying or advancing state transitions on the three or more connectors when the duration of the transition interval is estimated to be less than the threshold period, and

wherein each symbol defines one of at least three signaling states for each of the three or more connectors.

2. The method of claim 1 , wherein modifying operation of the one or more drivers causes temporal alignment of two or more outputs of state transition detection circuits in a receiver, wherein the state transition detection circuits are configured to compare signaling states of different pairs of the three or more connectors.

3. The method of claim 1 , wherein modifying the operation of the one or more drivers comprises:

configuring one or more delays to cause the driver to initiate a state transition on a first connector before a corresponding state transition is initiated on a second connector.

4. The method of claim 1 , wherein modifying the operation of the one or more drivers comprises:

configuring one or more delays to cause the driver to initiate a state transition on a first connector after a corresponding state transition is initiated on a second connector.

5. The method of claim 1 , wherein modifying the operation of the one or more drivers comprises:

configuring one or more delays to cause the driver to delay or advance initiation of a state transition on a first connector with respect to initiation of a corresponding state transition on a second connector.

6. The method of claim 1 , wherein modifying the operation of the one or more drivers comprises:

actively driving one connector during at least a portion of the transition interval when the duration of the transition interval is estimated to exceed the threshold period; and

refraining from driving the one connector while a second symbol of the pair of consecutive symbols is transmitted when the duration of the transition interval is estimated to be less than the threshold period.

7. The method of claim 1 , wherein estimating the duration of the transition interval includes:

determining a signaling state transition time for each of the three or more connectors relative to the symbol boundary; and

estimating delays between the symbol boundary and transitions in outputs of each of a plurality of differential receivers at a receiver,

wherein each of the plurality of differential receivers is coupled to a different pair of the three or more connectors.

8. The method of claim 1 , wherein the three or more connectors comprises at least three wires and at least one wire is in an undriven state during transmission of each symbol.

9. An apparatus, comprising:

a plurality of connectors communicatively coupling two devices in a terminal; and

a processing circuit configured to:

determine differences between each pair of consecutive symbols in a plurality of symbols to be transmitted on three or more connectors, wherein the differences relate to signaling states of the three or more connectors;

estimate a duration of a transition interval at a symbol boundary between the pair of consecutive symbols based on the differences; and

modify operation of one or more drivers of the three or more connectors to reduce the duration of the transition interval when the duration of the transition interval is estimated to exceed a threshold period,

wherein the processing circuit is configured to modify operation of one or more drivers by:

delaying or advancing an initiation of a state transition on at least one connector when the duration of the transition interval is estimated to exceed the threshold period; and

refraining from delaying or advancing state transitions on the three or more connectors when the duration of the transition interval is estimated to be less than the threshold period, and

wherein each symbol defines one of at least three signaling states for each of the three or more connectors.

10. The apparatus of claim 9 , wherein the operation of the one or more drivers is modified such that two or more outputs of state transition detection circuits in a receiver are temporally aligned, wherein the state transition detection circuits are configured to compare signaling states of different pairs of the three or more connectors.

11. The apparatus of claim 9 , wherein the processing circuit is configured to:

configure one or more delays to cause the driver to delay or advance initiation of a state transition on a first connector with respect to initiation of a corresponding state transition on a second connector.

12. The apparatus of claim 9 , wherein the processing circuit is configured to:

actively drive one connector during at least a portion of the transition interval when the duration of the transition interval is estimated to exceed the threshold period; and

refrain from driving the one connector while a second symbol of the pair of consecutive symbols is transmitted when the duration of the transition interval is estimated to be less than the threshold period.

13. The apparatus of claim 9 , wherein the processing circuit is configured to:

determine a signaling state transition time for each of the three or more connectors relative to the symbol boundary; and

estimate delays between the symbol boundary and transitions in outputs of each of a plurality of differential receivers at a receiver,

wherein each of the plurality of differential receivers is coupled to a different pair of the three or more connectors.

14. The apparatus of claim 9 , wherein the three or more connectors comprises at least three wires and at least one wire is in an undriven state during transmission of each symbol.

15. A data transfer method, comprising:

determining differences between each pair of consecutive symbols in a plurality of symbols to be transmitted on three or more connectors, wherein the differences relate to signaling states of the three or more connectors;

estimating a duration of a transition interval at a symbol boundary between the pair of consecutive symbols based on the differences; and

modifying operation of one or more drivers of the three or more connectors to reduce the duration of the transition interval when the duration of the transition interval is estimated to exceed a threshold period,

wherein modifying the operation of the one or more drivers comprises:

actively driving one connector during at least a portion of the transition interval when the duration of the transition interval is estimated to exceed the threshold period; or

refraining from driving the one connector while a second symbol of the pair of consecutive symbols is transmitted when the duration of the transition interval is estimated to be less than the threshold period, and

wherein each symbol defines one of at least three signaling states for each of the three or more connectors.

16. The method of claim 15 , wherein modifying operation of the one or more drivers causes temporal alignment of two or more outputs of state transition detection circuits in a receiver, wherein the state transition detection circuits are configured to compare signaling states of different pairs of the three or more connectors.

17. The method of claim 15 , wherein modifying the operation of the one or more drivers comprises:

configuring one or more delays to cause the driver to initiate a state transition on a first connector before a corresponding state transition is initiated on a second connector.

18. The method of claim 15 , wherein modifying the operation of the one or more drivers comprises:

configuring one or more delays to cause the driver to initiate a state transition on a first connector after a corresponding state transition is initiated on a second connector.

19. The method of claim 15 , wherein modifying the operation of the one or more drivers comprises:

configuring one or more delays to cause the driver to delay or advance initiation of a state transition on a first connector with respect to initiation of a corresponding state transition on a second connector.

20. The method of claim 15 , wherein modifying the operation of the one or more drivers comprises:

delaying or advancing an initiation of a state transition on at least one connector when the duration of the transition interval is estimated to exceed the threshold period; and

refraining from delaying or advancing state transitions on the three or more connectors when the duration of the transition interval is estimated to be less than the threshold period.

21. The method of claim 15 , wherein estimating the duration of the transition interval includes:

determining a signaling state transition time for each of the three or more connectors relative to the symbol boundary; and

estimating delays between the symbol boundary and transitions in outputs of each of a plurality of differential receivers at a receiver,

wherein each of the plurality of differential receivers is coupled to a different pair of the three or more connectors.

22. The method of claim 15 , wherein the three or more connectors comprises at least three wires and at least one wire is in an undriven state during transmission of each symbol.

23. An apparatus, comprising:

a plurality of connectors communicatively coupling two devices in a terminal; and

a processing circuit configured to:

determine differences between each pair of consecutive symbols in a plurality of symbols to be transmitted on three or more connectors, wherein the differences relate to signaling states of the three or more connectors;

estimate a duration of a transition interval at a symbol boundary between the pair of consecutive symbols based on the differences; and

modify operation of one or more drivers of the three or more connectors to reduce the duration of the transition interval when the duration of the transition interval is estimated to exceed a threshold period,

wherein the processing circuit is configured to modify operation of one or more drivers by:

actively driving one connector during at least a portion of the transition interval when the duration of the transition interval is estimated to exceed the threshold period; and

refraining from driving the one connector while a second symbol of the pair of consecutive symbols is transmitted when the duration of the transition interval is estimated to be less than the threshold period, and

wherein each symbol defines one of at least three signaling states for each of the three or more connectors.

24. The apparatus of claim 23 , wherein the operation of the one or more drivers is modified such that two or more outputs of state transition detection circuits in a receiver are temporally aligned, wherein the state transition detection circuits are configured to compare signaling states of different pairs of the three or more connectors.

25. The apparatus of claim 23 , wherein the processing circuit is configured to:

configure one or more delays to cause the driver to delay or advance initiation of a state transition on a first connector with respect to initiation of a corresponding state transition on a second connector.

26. The apparatus of claim 23 , wherein the processing circuit is configured to:

delay or advance an initiation of a state transition on at least one connector when the duration of the transition interval is estimated to exceed the threshold period; and

refrain from delaying or advancing state transitions on the three or more connectors when the duration of the transition interval is estimated to be less than the threshold period.

27. The apparatus of claim 23 , wherein the processing circuit is configured to:

determine a signaling state transition time for each of the three or more connectors relative to the symbol boundary; and

estimate delays between the symbol boundary and transitions in outputs of each of a plurality of differential receivers at a receiver,

wherein each of the plurality of differential receivers is coupled to a different pair of the three or more connectors.

28. The apparatus of claim 23 , wherein the three or more connectors comprises at least three wires and at least one wire is in an undriven state during transmission of each symbol.