N-phase signal transition alignment

Patent metadata

Field	Value
Publication number	US-9276731-B2
Application number	US-201414453346-A
Country	US
Kind code	B2
Filing date	Aug 6, 2014
Priority date	Aug 8, 2013
Publication date	Mar 1, 2016
Grant date	Mar 1, 2016

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 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 symb

Assignees

• Qualcomm Inc

Inventors

• Lee Chulkyu
• Wiley George Alan

Classifications

• H04L25/4917

  using multilevel codes · CPC title

• G06F13/4295

  using an embedded synchronisation · CPC title

• G06F13/4282

  on a serial bus, e.g. I2C bus, SPI bus (on daisy chain buses G06F13/4247) · CPC title

• G06F13/4068

  Electrical coupling · CPC title

• G06F13/4063

  Device-to-bus coupling · CPC title