Multiwavelength Bus Distribution for Concurrent Buffer IC Reception

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing bus distribution systems in optical communication face challenges in efficiently transmitting command/address and synchronization/timing information to multiple buffer integrated circuits using a single waveguide, leading to interference and inefficiencies.

Innovation Solution

The implementation of multiwavelength multiplexing using wavelength resonant ring couplers to separate and direct different wavelengths of light to specific buffer devices, allowing for concurrent and multidrop reception of command/address and timing information.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single waveguide is used to transmit information to multiple buffer integrated circuits, then the device complexity is reduced, but interference occurs between different information streams

Engineering Contradiction:

Improvewaveguide structureVSAvoidinterference between information streams

Core Design Contradiction:

Device complexityVSObject-affected harmful factors

Solution Approach 1:

The patent applies wavelength division multiplexing by assigning different wavelength parameters to different information streams (command/address vs. synchronization/timing). This allows multiple streams to coexist in the same waveguide without interference, as each wavelength can be independently filtered and received by appropriate buffer circuits.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent segments the information transmission by separating command/address information and synchronization/timing information into distinct wavelength channels. Each buffer integrated circuit is equipped with wavelength-selective filters that segment and direct specific wavelengths to the appropriate destinations, preventing interference while maintaining a single waveguide infrastructure.

Inventive Principle:

Principle #1Segmentation

2Productivity

If multiple wavelengths are multiplexed on a single waveguide, then the transmission efficiency is improved, but the device complexity increases due to wavelength resonant ring couplers

Engineering Contradiction:

Improvetransmission efficiencyVSAvoidwavelength resonant ring couplers

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent implements wavelength resonant ring couplers that are nested within or integrated with the buffer integrated circuits. These couplers selectively extract specific wavelengths from the multiplexed stream passing through the waveguide, allowing efficient demultiplexing without requiring separate complex external filtering systems for each buffer circuit.

Inventive Principle:

Principle #7Nested doll (Nesting)

Solution Approach 2:

The wavelength resonant ring couplers serve multiple functions: they act as wavelength-selective filters, signal directors, and interface components between the optical waveguide and electrical buffer circuits. This multi-functionality reduces the need for separate dedicated components for each function, thereby managing complexity while maintaining high transmission efficiency.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Speed

If concurrent reception of command/address and timing information is implemented, then the speed is improved, but interference between simultaneous transmissions may occur

Engineering Contradiction:

Improvereception speedVSAvoidinterference between simultaneous transmissions

Core Design Contradiction:

SpeedVSObject-affected harmful factors

Solution Approach 1:

The patent enables concurrent reception by assigning different wavelength parameters to command/address information and synchronization/timing information. Buffer integrated circuits use wavelength-selective filtering to simultaneously receive and process both types of information without interference, as each wavelength channel operates independently within the same physical medium.

Inventive Principle:

Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach enables efficient, interference-free transmission of information to multiple buffer integrated circuits, enhancing the reliability and speed of optical bus communication.

Implementation Method 1

wavelength resonant ring couplers to separate and direct different wavelengths of light to specific buffer devices

Methodology Applied

Scientific EffectOptical resonance: Resonance

Implementation Method 2

transmitted on the same waveguide

Methodology Applied

Scientific EffectOptical waveguide transmission: Waveguide (optics)

Data Source

PatentUS20250321379A1Bus distribution using multiwavelength multiplexing

Publication Date: 2025.10.16 RAMBUS INC

AI summary

Command/address and timing information is distributed to buffer integrated circuits on a module using multiple wavelengths of light modulated with the same information. Each individual wavelength of modulated light carrying command/address information is received by a corresponding single buffer device that deserializes the command/address information and communicates it electrically to memory devices(s). Likewise, each individual wavelength of modulated light carrying timing/synchronization/clock information is received by a corresponding single buffer device and used to synchronize accesses to the memory device(s). Thus, multiple buffer integrated circuits on a module each receive information from the CPU using different wavelengths of light transmitted on the same waveguide.