Method and apparatus for identifying content addressable memory device results for multiple requesting sources
View Patent ↗A system ( 100 ) may include a content addressable memory (CAM) device ( 102 ) and at least two requesting devices ( 104 - 0 and 104 - n ). Requesting devices ( 104 - 0 and 104 - n ) and a CAM device ( 102 ) may be connected by at least two communication links ( 106 - 0 and 106 - n ). A CAM device ( 102 ) may generate responses to requests, and assign a flow identification value for responses based on a communication link ( 106 - 0 and 106 - n ) on which a corresponding request was received.
1. A content addressable memory (CAM) device, comprising:
at least one CAM array having a plurality of CAM entries; and
a flow identification (ID) generating circuit that generates a flow ID value for a response resulting from a corresponding request, each flow ID value corresponding to an input from which the corresponding request is received.
2. The CAM device of claim 1 , wherein:
the CAM device includes a plurality of input communication links, each input communication link receiving requests from a different requesting source.
3. The CAM device of claim 2 , further including:
a multiplexer that inputs a request from one of a plurality of input communication links.
4. The CAM device of claim 3 , wherein:
the multiplexer inputs a request according to control signals that correspond to flow ID values.
5. The CAM device of claim 1 , further including:
a de-multiplexer that outputs a response on one of a plurality of communication links according to the flow ID value for the response.
6. The CAM device of claim 1 , further including:
a scheduler that generates control signals for inputting request data on one of a plurality of inputs; and
wherein each flow ID values is generated in response to the control signals.
7. The CAM device of claim 6 , further including:
a plurality of first-in-first-out (FIFO) buffer circuits, each coupled to a different input and receiving requests from a different request source and providing status data corresponding to the amount of data in the FIFO buffer circuit to the scheduler.
8. A content addressable memory (CAM) device, comprising:
at least one CAM array;
a de-multiplexer that outputs a response on one of a plurality of output communication links according to at least one flow identification (ID) value associated with the response; and
an input multiplexer that provides a data path between one of a plurality of input communication links and a first data path according to control signals.
9. The CAM device of claim 8 , further including:
a flow ID value generating circuit that generates flow ID values for responses based on an input communication link on which a corresponding request is received.
10. The CAM device of claim 8 , further including:
a select multiplexer having one input coupled to an input data path and another input coupler to the CAM array.
11. The CAM device of claim 10 , further including:
an output store, coupled to an output of the select multiplexer, for storing flow ID values and responses.
12. The CAM device of claim 10 , further including:
an intermediate store for storing flow ID values, the intermediate store being coupled to an input of the select multiplexer.
13. The CAM device of claim 8 , further including:
a plurality of first-in-first-out (FIFO) buffer circuits, each coupled between an output of the de-multiplexer and one of the output communication links.
14. The CAM device of claim 8 , further including:
an input multiplexer that provides a data path between one of a plurality of input communications links and a first data path according to control signals.
15. A method of executing requests in a CAM system, comprising the steps of:
a receiving requests from multiple different sources on input communication links; and
assigning a flow identification (ID) value to a response that corresponds to the input communication link on which a request that generates the response was received.
16. The method of claim 15 , further including the step:
generating responses corresponding to the requests within at least one CAM device.
17. The method of claim 16 , wherein:
the requests are selected from the group consisting of: search operation, read operation, write operation, learn operation, and parity check operations.
18. The method of claim 15 , further including the steps:
storing the flow ID value; and
outputting the flow ID value with response data to an output store.
19. The method of claim 15 , further including the steps:
storing the flow ID value in a first portion of an output store; and
subsequently outputting response data to a second portion of the output store.
20. A content addressable memory (CAM), comprising:
at least one communication link; and
the CAM configured to include flow information to an incoming command corresponding to the link on which the command was received.