N-phase signal transition alignment

Patent metadata

Field	Value
Publication number	US-10127167-B2
Application number	US-201615373645-A
Country	US
Kind code	B2
Filing date	Dec 9, 2016
Priority date	Aug 8, 2013
Publication date	Nov 13, 2018
Grant date	Nov 13, 2018

Abstract

System, methods and apparatus are described that facilitate transmission of data, particularly between two devices within an electronic apparatus. Information is transmitted in N-phase polarity encoded symbols. Drivers may be adapted or configured to align state transitions on two or more connectors in order to minimize a transition period between consecutive symbols. The drivers may include circuits that advance or delay certain transitions. The drivers may include pre-emphasis circuits that operate to drive the state of a connector for a portion of the transition period, even when the connector is transitioned to an undriven state.

First claim

What is claimed is:

1. A method for data communications, comprising:
determining a transition in signaling state of three wires of a communication link between a pair of consecutive symbols transmitted on the communication link, wherein each symbol defines a different signaling state of the three wires of the communication link; and
selectively increasing driver strength prior to the transition in signaling state of the three wires when the transition in signaling state includes a change in signaling state of a corresponding wire on which a signal is transmitted,
wherein during transmission of a first symbol in the pair of consecutive symbols, a first wire of the three wires and a second wire of the three wires are at voltage levels that have different polarities from one another, and
wherein during transmission of a second symbol in the pair of consecutive symbols, the first wire and a third wire of the three wires are at the voltage levels that have different polarities from one another.

2. The method of claim 1 , wherein during transmission of the first symbol the third wire has a voltage that lies substantially halfway between voltage levels of the first wire and the second wire.

3. The method of claim 1 , wherein driver strength is increased when the change in signaling state of the corresponding wire includes a polarity change of the signal.

4. The method of claim 1 , wherein driver strength is not increased when the change in signaling state of the corresponding wire does not include a polarity change of the signal.

5. The method of claim 1 , and further comprising:
initiating transmission of the second symbol on one wire before transmission of the first symbol is terminated.

6. The method of claim 1 , and further comprising:
initiating transmission of the second symbol on one wire after transmission of the first symbol is terminated.

7. The method of claim 1 , wherein driver strength is increased or not increased based on signaling state of all three wires after the transition.

8. The method of claim 7 , wherein driver strength is increased or not increased based on changes in relative signaling states of each pairing of wires in the three wires.

9. The method of claim 7 , wherein driver strength is increased or not increased based on changes in signaling state of all three wires.

10. The method of claim 7 , wherein increasing driver strength comprises:
adding pre-emphasis to one or more driver outputs based on prior knowledge of a type of transition in signaling state of the three wires of the communication link between the pair of consecutive symbols.

11. An apparatus, comprising:
means for determining a transition in signaling state of three wires of a communication link between a pair of consecutive symbols transmitted on the communication link, wherein each symbol defines a different signaling state of the three wires of the communication link; and
means for selectively increasing driver strength prior to the transition in signaling state of the three wires when the transition in signaling state includes a change in signaling state of a corresponding wire on which a signal is transmitted,
wherein during transmission of a first symbol in the pair of consecutive symbols, a first wire of the three wires and a second wire of the three wires are at voltage levels that have different polarities from one another, and
wherein during transmission of a second symbol in the pair of consecutive symbols, the first wire and a third wire of the three wires are at the voltage levels that have different polarities from one another.

12. The apparatus of claim 11 , wherein during transmission of the first symbol the third wire has a voltage that lies substantially halfway between voltage levels of the first wire and the second wire.

13. The apparatus of claim 11 , wherein driver strength is increased when the change in signaling state of the corresponding wire includes a polarity change of the signal, and wherein driver strength is increased when the change in signaling state of the corresponding wire includes a polarity change of the signal.

14. The apparatus of claim 11 , further comprising:
means for selectively initiating transmission of the second symbol on one wire before or after transmission of the first symbol is terminated.

15. The apparatus of claim 11 , wherein driver strength is increased or not increased based on signaling state of all three wires after the transition.

16. The apparatus of claim 11 , wherein driver strength is increased or not increased based on changes in relative signaling states of each pairing of wires in the three wires.

17. The apparatus of claim 16 , wherein driver strength is increased or not increased based on changes in signaling state of all three wires.

18. The apparatus of claim 16 , wherein the means for selectively increasing driver strength is configured to add pre-emphasis to one or more driver outputs based on prior knowledge of a type of transition in signaling state of the three wires of the communication link between the pair of consecutive symbols.

19. An apparatus, comprising:
a processing circuit configured to:
determine a transition in signaling state of three wires of a communication link between a pair of consecutive symbols transmitted on the communication link, wherein each symbol defines a different signaling state of the three wires of the communication link; and
selectively increase driver strength prior to the transition in signaling state of the three wires when the transition in signaling state includes a change in signaling state of a corresponding wire on which a signal is transmitted,

wherein during transmission of a first symbol in the pair of consecutive symbols, a first wire of the three wires and a second wire of the three wires are at voltage levels that have different polarities from one another, and
wherein during transmission of a second symbol in the pair of consecutive symbols, the first wire and a third wire of the three wires are at the voltage levels that have different polarities from one another.

20. The apparatus of claim 19 , wherein driver strength is increased when the change in signaling state of the corresponding wire includes a polarity change of the signal, and wherein driver strength is increased when the change in signaling state of the corresponding wire includes a polarity change of the signal.

21. The apparatus of claim 19 , wherein the processing circuit is configured to:
selectively initiate transmission of the second symbol on one wire before or after transmission of the first symbol is terminated.

22. The apparatus of claim 19 , wherein the processing circuit is configured to pre-emphasize the signal by initiating the transmission of the second symbol before the transmission of the first symbol is terminated.

23. The apparatus of claim 19 , wherein driver strength is increased or not increased based on changes in relative signaling states of each pairing of wires in the three wires.

24. The apparatus of claim 19 , wherein the processing circuit is configured to:
add pre-emphasis to one or more driver outputs based on prior knowledge of a type of transition in signaling state of the three wires of the communication link between the pair of consecutive symbols.

25. A non-transitory processor-readable storage medium having one or more instructions which, when executed by at least one processing circuit, ca

Assignees

• Qualcomm Inc

Inventors

• Lee Chulkyu
• Wiley George Alan

Classifications

• G06F13/4063

  Device-to-bus coupling · CPC title

• H04L7/0033

  Correction by delay · CPC title

• H04L25/4917

  using multilevel codes · CPC title

• H04L25/4919

  using balanced multilevel codes (H04L25/4927 takes precedence) · CPC title

• G06F13/4068

  Electrical coupling · CPC title