Patent ID: 7970990

Claim:
A memory system, comprising: a memory controller; a first memory module and a second memory module, where each memory module comprises a memory buffer and a random-access memory device; and an optical channel that supports wavelength-division multiplexing; wherein the memory controller is coupled in series first to the first memory module and to the second memory module using the optical channel; wherein the memory buffer in a memory module is configured to receive a request from the memory controller via the optical channel, handle the request by accessing the random-access memory device, and send a response to the memory controller via the optical channel; wherein the first memory module is configured to monitor for and respond to requests in the optical channel that are encoded in a first wavelength and the second memory module is configured to monitor for and respond to requests in the optical channel that are encoded in a second wavelength; and wherein the first memory module removes the first wavelength from the optical channel while passing the second wavelength through without delay and without electrical conversion, thereby reducing request latency for requests not intended for the first memory module.