Asymmetric Voltage Swing Interface for IC Interconnects

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Solution Overview

Problem

The electrical interface between integrated circuits, particularly between a controller and memory elements, remains a significant limiting factor for memory performance due to differences in semiconductor technology, threshold voltages, and packaging technologies, leading to inefficient power consumption and communication challenges in high-speed link designs.

Innovation Solution

Implementing an asymmetric voltage swing interface where the controller transmitter uses a higher voltage swing than the memory transmitter, optimizing power efficiency by reducing overall power dissipation and improving receiver sensitivity through better signal management and packaging considerations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If symmetric voltage swing is used in both directions of the interface, then simplicity of design is maintained, but power consumption increases and receiver sensitivity decreases

Engineering Contradiction:
Improvepower consumptionVSAvoidinterface design complexity
Core Design Contradiction:
Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The patent applies asymmetry by implementing different voltage swing values for transmissions in opposite directions across the interface. Specifically, one direction uses a larger voltage swing while the reverse direction uses a smaller voltage swing, optimizing power consumption and signal integrity for each direction based on the specific electrical characteristics and requirements of that transmission path.

Inventive Principle:
Principle #4Asymmetry

2Reliability

If higher voltage swing is used to improve receiver sensitivity, then communication reliability improves, but power dissipation increases

Engineering Contradiction:
Improvecommunication reliabilityVSAvoidpower dissipation
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent applies local quality by tailoring the voltage swing parameter to the specific requirements of each transmission direction. Each interface channel uses a customized voltage swing value that provides sufficient signal integrity for that particular direction while minimizing unnecessary power consumption, rather than applying a uniform voltage swing across all channels.

Inventive Principle:
Principle #3Local quality

3Ease of operation

If full CMOS swing is used in both directions, then signal integrity is maintained, but power efficiency deteriorates

Engineering Contradiction:
Improvesignal integrityVSAvoidpower efficiency
Core Design Contradiction:
Ease of operationVSUse of energy by moving object

Solution Approach 1:

The patent applies parameter changes by dynamically adjusting the voltage swing parameter based on the transmission direction and the electrical characteristics of each interface channel. This optimization of the voltage swing parameter improves power efficiency while maintaining adequate signal integrity for reliable communication in both directions.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2898416B1Interfacing between integrated circuits with asymmetric voltage swing
Publication Date: 2019.09.25 LATTICE SEMICON CORP
  • EP2898416B1 patent drawingFigure 1A~1B
  • EP2898416B1 patent drawingFigure 2A~2B
  • EP2898416B1 patent drawingFigure 3

AI summary

Embodiments of the invention are generally directed to interfacing between integrated circuits with asymmetric voltage swing. An embodiment of an apparatus includes a first integrated circuit including a first transmitter and a first receiver; a second integrated circuit including a second transmitter and a second receiver; and an interface including communication channel linking the first transmitter with the second receiver and the first receiver with the second transmitter, wherein the communication channel is one of a single channel or a dual channel. The first transmitter is operable to transmit a first signal and the second transmitter is operable to transmit a second signal, a first average voltage swing of the first signal being asymmetric with a second average voltage swing of the second signal.