US 12,292,601 B2Granted

Bus distribution using multiwavelength multiplexing

AssigneeRambus Inc.

InventorsMark D. Kellam, Dongyun Lee, Thomas Vogelsang, Steven C. Woo

Life of this patent

Estimating the term…

Loading patent…

Abstract

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.

Claims20

Dependent claims

A module, comprising:

a first buffer die including a first silicon waveguide to receive a first light wave carrier and a second light wave carrier, the first buffer die to couple the first light wave carrier to a first optical to electrical interface;
a second buffer die including a second silicon waveguide to receive the second light wave carrier, the second buffer die to couple the second light wave carrier to a second optical to electrical interface;
a first optical interface to receive the first light wave carrier, carrying first command/address information, from a host system into a first polymer waveguide disposed on the module, and to receive the second light wave carrier, also carrying the first command/address information, from the host system into the first polymer waveguide;
and,
the first polymer waveguide to couple the first light wave carrier and the second light wave carrier into the first silicon waveguide, and to receive the second light wave carrier back from the first silicon waveguide, and to couple the second light wave carrier into the second silicon waveguide.

2 more elements

A method of operating a module, comprising:

receiving, from a host system and via a first optical interface of the module, a first light wave carrier carrying command/address information;
receiving, from the host system and via the first optical interface of the module, a second light wave carrier carrying the command/address information;
coupling the first light wave carrier and the second light wave carrier into a first polymer waveguide disposed on the module;
coupling the first light wave carrier and the second light wave carrier from the first polymer waveguide into a first silicon waveguide disposed on a first integrated circuit;
extracting, by the first integrated circuit, the command/address information carried by the first light wave carrier;
coupling the second light wave carrier back from the first silicon waveguide into the first polymer waveguide;
coupling the second light wave carrier received back from the first silicon waveguide into a second silicon waveguide disposed on a second integrated circuit;
and
extracting, by the second integrated circuit, the command/address information carried by the second light wave carrier.

6 more elements

Dependencies are inferred from the claim text.

Facts

Application: 17/963,065Filed 10 Oct 2022 · us provisional application
Priority: 26 Oct 2021
Published: US 2023/0125262 A127 Apr 2023
Granted: 6 May 2025
Term ends: Not estimatedThe source records don’t support an estimate.

Classification7 codes

G02B 6/2938
Characterised by the function or use of the complete device: for multiplexing or demultiplexing, i.e. combining or separating wavelengths, e.g.…
G02B 6/12007
Of the integrated circuit kind: forming wavelength selective elements, e.g. multiplexer, demultiplexer
H04B 10/506
Structural aspects: multiwavelength transmitters
H04J 14/028
WDM optical network architectures: wDM bus architectures