Apparatus and method for interoperability between SAS and PCI express

1. A serial attached small computer system interface (SAS)—peripheral component interconnect express (PCIe) bridge for enabling interoperability between a SAS protocol and a PCIe protocol, the SAS-PCIe bridge comprising:

a SAS component configured to communicate with a SAS device in a SAS domain; and

a PCIe component configured to communicate with a PCIe switch in a PCIe domain;

the SAS component and the PCIe component being configured to convert data between the SAS protocol and the PCIe protocol, the data including SAS data having SAS link layer primitives and frames,

the PCIe component being configured to encapsulate the SAS link layer primitives and frames into PCIe packets.

2. The SAS-PCIe bridge of claim 1 , wherein:

the SAS component is configured to receive the SAS data from a SAS device in the SAS domain; and

the PCIe component is configured to send the PCIe packets to a second SAS-PCIe bridge in the PCIe domain.

3. The SAS PCIe bridge of claim 2 , wherein the second SAS-PCIe bridge is configured to regenerate the SAS data from the PCIe packets.

4. The SAS-PCIe bridge of claim 1 , wherein the data includes PCIe data having PCIe packets and wherein the PCIe component is configured to:

generate SAS link layer primitives and frames from the PCIe packets.

5. The SAS-PCIe bridge of claim 4 , wherein:

the PCIe component is configured to receive the PCIe packets; and

the SAS component is configured to send the SAS link layer primitives and frames to the SAS device in the SAS domain.

6. The SAS-PCIe bridge of claim 1 , wherein the SAS component is presented to the SAS device as a standard SAS expander.

7. The SAS-PCIe bridge of claim 1 , wherein the SAS component and the PCIe component convert the data between the SAS protocol and the PCIe protocol using PCIe memory write transport layer packets.

8. The SAS-PCIe bridge of claim 1 , wherein the SAS component and the PCIe component convert the data between the SAS protocol and the PCIe protocol using PCIe protocol multiplexing extensions.

9. The SAS-PCIe bridge of claim 1 , wherein the SAS component and the PCIe component convert the data between the SAS protocol and the PCIe protocol using proprietary PCIe packets.

10. A method for enabling interoperability between a serial attached small computer system interface (SAS) protocol and a peripheral component interconnect express (PCIe) protocol, the method comprising:

receiving SAS link layer primitives and frames from a SAS device in a SAS domain;

encapsulating the SAS link layer primitives and frames into PCIe packets; and

sending the PCIe packets to a PCIe switch in a PCIe domain.

11. The method of claim 10 , wherein the PCIe packets comprise PCIe memory write transport layer packets.

12. The method of claim 10 , wherein the PCIe packets use PCIe protocol multiplexing extensions.

13. The method of claim 10 , wherein the PCIe packets comprise proprietary PCIe packets.

14. A method for enabling interoperability between a serial attached small computer system interface (SAS) protocol and a peripheral component interconnect express (PCIe) protocol, the method comprising:

receiving data including SAS data having SAS link layer primitives and frames from a SAS device in a SAS domain;

encapsulating the SAS link layer primitives and frames into PCIe packets; and

sending the PCIe packets to a PCIe switch in the PCIe domain.

15. The method of claim 14 , wherein the PCIe packets include PCIe memory write transport layer packets.

16. The method of claim 14 , wherein the PCIe packets use PCIe protocol multiplexing extensions.

17. The method of claim 14 , wherein the PCIe packets include proprietary PCIe packets.

18. A data communications device comprising:

a serial attached small computer system interface (SAS)—peripheral component interconnect express (PCIe) bridge for enabling interoperability between a SAS protocol and a PCIe protocol, the SAS-PCIe bridge comprising:

a SAS component configured to communicate with a SAS device in a SAS domain; and

a PCIe component configured to communicate with a PCIe switch in a PCIe domain;

the SAS component and the PCIe component being configured to convert data between the SAS protocol and the PCIe protocol, the data including SAS data having SAS link layer primitives and frames,

the PCIe component being configured to encapsulate the SAS link layer primitives and frames into PCIe packets.

19. The data communications device of claim 18 wherein the data communications device comprises an input-output controller.