Time division multiplexing (TDM) based optical ternary content addressable memory (TCAM)
AssigneeHewlett Packard Enterprise Development LP
InventorsThomas Van Vaerenbergh, Can Li, Catherine Graves
Life of this patent
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Abstract
Systems and methods for an optical ternary content addressable memory (TCAM) are provided. The optical TCAM implements a time-division multiplexing (TDM) based encoding scheme to encode each bit position of a search word in the time domain. Each bit position is associated with at least two time slots. The encoded optical signal comprising the search word is routed through one or more modulators configured to represent a respective TCAM stored word. If a mismatch between at least one bit position of the search word and at least one TCAM stored word occurs, a photodetector or photodetector array will detect light.
Claims7
A optical ternary content addressable memory (TCAM) comprising:
- an input encoder configured to encode a search word on an optical search signal, wherein each bit position of the search word is represented by at least two time slots of a clock signal;
- a splitter optically coupled to an output of the input encoder configured to generate a plurality of copies of the optical search signal;
- a multi-word encoder configured to generate a plurality of TCAM word signals, each TCAM word signal encoding a TCAM stored word of a plurality of TCAM stored words and wherein each bit position of the TCAM stored word is represented by at least two time slots of the clock signal;
- an optical interleaver configured to route a copy of the optical search signal of the plurality of copies of the optical search signal and a TCAM word signal of the plurality of TCAM word signals to propagate in parallel as a plurality of pairs of inputted signals;
- a plurality of multipliers, each multiplier configured to receive a pair of inputted signals of the plurality of pairs of inputted signals and compare the respective copy of the plurality of copies of the optical search signal and the respective TCAM word signal;
- and
- a plurality of balanced photodetectors arrays, each balanced photodetector array optically coupled to an output of a respective multiplier of the plurality of multipliers,
- wherein each balanced photodetector array is configured to detect a mismatch between the respective copy of the plurality of copies of the optical search signal output from a first output of a respective multiplier and the respective TCAM word signal output from a second output of the respective multiplier by detecting light during at least one time slot of the clock signal.
Dependencies are inferred from the claim text.