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US 12,712,019 B2Granted
Photonic content addressable memory
AssigneeWisconsin Alumni Research Foundation
InventorsZihan Yin, Akhilesh Jaiswal
Life of this patent
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Abstract
A photonic content addressable memory employs cross coupled optical inverters to provide a bistable element that can be set or reset and interrogated optically. Optical switches controlled by the state of the bistable element can compare that state to optically conveyed pattern bits providing a “wired OR” on an output line quickly indicating matching along a logical row of data so stored. The bistable element can be simultaneously interrogated with different search patterns using parallel banks of optical switches tuned to different frequencies.
Claims11
An optical content addressable memory comprising:
- a set of memory cells each providing:
- a first and a second optical switch each having an input and output determining a switch state, with the output of the first optical switch connected to the input of the second optical switch and the output of the second optical switch connected to the input of the first optical switch, each optical switch operating as an inverter to produce a bistable element;
- a third and fourth optical switch each receiving an input determining a switch state, the input determined by the output of the first and second optical switches respectively;
- a first and second content input line providing independent optical signals to the third and fourth optical switches respectively denoting a search pattern;
- and
- a content output line receiving an optical signal from both of the third and fourth optical switches to provide a logical OR of those optical signals.
3 more elements
An optical content addressable memory comprising:
- a set of memory cells each providing:
- a first and a second optical switch each having an input and output, with the output of the first optical switch connected to the input of the second optical switch and the output of the second optical switch connected to the input of the first optical switch, each optical switch operating as an inverter to produce a bistable element;
- a third and fourth optical switch each receiving an input determined by the output of the first and second optical switches respectively;
- a first and second content input line providing independent optical signals to the third and fourth optical switches respectively denoting a search pattern;
- and
- a content output line receiving an optical signal from both of the third and fourth optical switches to provide a logical OR of those optical signals;
- further including a fifth and sixth optical switch each receiving an input determined by an output of the first and second optical switches respectively;
- a memory cell read line providing an optical signal to both of the fifth and sixth optical switches;
- a first and second memory cell output line receiving an optical signal from the fifth and sixth optical switches respectively to provide respective complementary outputs indicating a state of the bistable element;
- and
- further including a seventh and eighth optical switch each providing a respective output to the inputs of the first and second optical switches;
- a memory cell write line providing an optical signal to both of the seventh and eighth optical switches;
- and
- a first and second memory cell input line providing respective and mutually complementary optical signals to the inputs of the first and second optical switches to override their states.
11 more elements
An optical content addressable memory comprising:
- a set of memory cells each providing:
- a first and a second optical switch each having an input and output, with the output of the first optical switch connected to the input of the second optical switch and the output of the second optical switch connected to the input of the first optical switch, each optical switch operating as an inverter to produce a bistable element;
- a third and fourth optical switch each receiving an input determined by the output of the first and second optical switches respectively;
- a first and second content input line providing independent optical signals to the third and fourth optical switches respectively denoting a search pattern;
- and
- a content output line receiving an optical signal from both of the third and fourth optical switches to provide a logical OR of those optical signals;
- wherein the first and second optical switches are hybrid electrical photonic devices.
4 more elements
Dependencies are inferred from the claim text.