Granted Patent B1

US 7,426,608 · App. 10/789,668 · Granted Sep 16, 2008

Abstract

Claims (44)

1. A search key construction system, comprising:

a plurality of search key sections, wherein each section is coupled to an output of a first multiplexer having a first programmable control;

a second multiplexer having a second programmable control and an output coupled to the first multiplexer; and

a third multiplexer having a third programmable control and an output coupled to the first multiplexer.

2. The search key construction system of claim 1 , wherein:

the plurality of search key sections is configured to substantially form a search key for a memory bank.

3. The search key construction system of claim 1 , wherein:

the first programmable control includes a key source select configured to enable one of a first type path, a second type path, and a third type path.

4. The search key construction system of claim 3 , wherein:

the first type path includes one of a plurality of designated section positions from a packet header.

5. The search key construction system of claim 3 , wherein:

the second type path includes a short field from a packet attribute.

6. The search key construction system of claim 5 , wherein:

the short field includes a width of at most 16-bits.

7. The search key construction system of claim 3 , wherein:

the third type path includes a long field from a packet header.

8. The search key construction system of claim 7 , wherein:

the long field includes a width of at least 128-bits.

9. The search key construction system of claim 1 , wherein:

the second programmable control includes a short field selection signal.

10. The search key construction system of claim 1 , wherein:

the third programmable control includes a long field selection signal.

11. The search key construction system of claim 1 , wherein:

each of the plurality of search key sections is 16-bits wide.

12. The search key construction system of claim 2 , wherein;

the memory bank includes Ternary Content Addressable Memory (TCAM).

13. The search key construction system of claim 2 , wherein:

the memory bank includes Static Random Access Memory (SRAM).

14. A method of constructing a search key, comprising the steps of:

programming bank key construction settings,

passing a first type programmed field to a key section if a first type path is enabled;

passing a second type programmed field to the key section if a second type path is enabled; and

passing a third type field to the key section if the first type path and the second type path are both disabled.

15. The method of constructing a search key of claim 14 , wherein:

the first type path includes a long field from a packet header.

16. The method of constructing a search key of claim 14 , wherein:

the second type path includes a short field from a packet attribute.

17. The method of constructing a search key of claim 14 , wherein:

the third type field includes one of a plurality of designated section positions from a packet header.

18. A means for constructing a search key, comprising:

a means for programming bank key construction settings;

a means for passing a first type programmed field to a key section if a first type path is enabled;

a means for passing a second type programmed field to the key section if a second type path is enabled; and

a means for passing a third type field to the key section if the first type path and the second type path are both disabled.

Assignments (13)