Method and apparatus for an improved interface between computer components

• US 6,145,039 A
• Filed: 11/03/1998
• Issued: 11/07/2000
• Est. Priority Date: 11/03/1998
• Status: Expired due to Term

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Ajanovic, Jasmin, Harriman, David J.
• Primary Examiner(s): Shin, Christopher B.
• Application Number:
  US09/186,219
• Time in Patent Office: 735 Days
• Field of Search: 710/36-40, 710/58-61, 710/1.7-244
• US Class Current: 710/105
• CPC Class Codes: G06F 13/4208 being a system bus, e.g. VME bus, Futurebus, Multibus

Abstract

An interface to transfer data between a memory controller hub and an input/output (I/O) hub of a chipset within a computer system. One embodiment of the interface includes a bi-directional data signal path and a pair of source synchronous strobe signals. The data signal path transmits data in packets via split transactions. In addition, the packets include a request packet and a completion packet, if necessary. Furthermore, in one embodiment, the request packets include a transaction descriptor.

Claims

1. An interface to transfer data directly between a first hub and a second hub within a computer system, comprising:

a data signal path to transmit data in packets via split transactions; and

a set of command signals, wherein said interface provides a point-to-point connection between said first hub and said second hub, exclusive of an external bus connected directly to the interface.

2. The interface of claim 1, wherein said first and second hubs within said computer system are components within a chipset.

4. The interface of claim 1, wherein a first transaction is initiated on said interface with a request packet, subsequent to arbitration for ownership of said interface.

5. The interface of claim 4, wherein said request packet includes a transaction descriptor.

6. The interface of claim 4, wherein a completion packet is transmitted on said interface in response to said request packet of said first transaction.

7. The interface of claim 5, wherein said request packet includes a transaction descriptor and said completion packet includes a corresponding transaction descriptor.

8. The interface of claim 6, wherein a request packet for a second transaction can be transmitted across said interface prior to transmitting said completion packet in response to the request packet of said first transaction.

9. The interface of claim 8, wherein said first is a memory controller hub to interconnect a processor and a memory device.

10. The interface of claim 9, wherein a second hub is an input/output (I/O) hub to interconnect peripheral components within a computer system.

11. The interface of claim 1, wherein said data signal path is scalable.

12. The interface of claim 11, wherein packets are transmitted across said data signal path via a source synchronous clock mode.

13. The interface of claim 12, wherein said interface includes a set of bi-directional data signals, a first and second source synchronous strobe signal, a unidirectional arbitration signal, and a bidirectional stop signal.

14. The interface of claim 13, wherein said interface further includes a system reset signal, a common clock signal, and a voltage reference signal.

15. The interface of claim 7, wherein said transaction descriptors identify separate hubs within a hierarchy of multiple interfaces between at least three hubs.

16. The interface of claim 6, wherein said request packet includes a field indicating if a completion packet is required in response to the respective request packet.

17. The interface of claim 4, wherein arbitration between said hubs is symmetric and distributed.

18. The interface of claim 4, wherein a hub is allotted ownership of said interface up to a predetermined amount of time.

3. An interface to transfer data between a first hub and a second hub within a computer system, comprising:

a set of data signals and a pair of source synchronous strobe signals, said data signals transmit data in packets via split transactions, said packets including a request packet and completion packet, said request packet including a transaction descriptor; and

a set of command signals including unidirectional arbitration signal and a common clock signal, wherein said interface provides a point-to-point connection between said first hub and said second hub, exclusive of an external bus connected directly to the point-to-point connection.

19. An interface to transfer data directly between a first hub and a second hub within a computer system, comprising:

a first means for transmitting data between said first hub and said second hub in packets via split transactions; and

a second means for transmitting command signals, wherein said interface provides a point-to-point connection between said first hub and said second hub, exclusive of an external bus connected directly to the interface.

20. The interface of claim 19, wherein said first and second hubs within said computer system are components within a chipset.

22. The interface of claim 19, wherein said interface includes a means for initiating a first transaction on said interface with a request packet.

23. The interface of claim 22, wherein said request packet includes a transaction descriptor.

24. The interface of claim 22, wherein said interface includes means for providing a completion packet in response to said request packet of said first transaction.

25. The interface of claim 23, wherein said request packet includes a transaction descriptor and said completion packet includes a corresponding transaction descriptor.

26. The interface of claim 24, wherein said interface includes a means for transmitting request packet for a second transaction across said interface prior to transmitting said completion packet in response to the request packet of said first transaction.

27. The interface of claim 26, wherein said first hub is a memory controller hub having a means to interconnect a processor and a memory device.

28. The interface of claim 27, wherein said second hub is an input/output (I/O) hub having a means to interconnect peripheral components within a computer system.

29. The interface of claim 19, wherein said first means for transmitting data in packets via split transactions includes further includes means for scaling a data signal path.

30. The interface of claim 26, wherein said interface includes means for transmitting packets across said interface via a source synchronous clock mode.

31. The interface of claim 25, wherein said transaction descriptors include a means for identifying separate hubs within a hierarchy of multiple interfaces between three or more hubs.

32. The interface of claim 24, wherein said request packet includes a means for indicating if a completion packet is required in response to the respective request packet.

33. The interface of claim 32, wherein interface includes a means for arbitrating between said hubs for ownership of said interface.

34. The interface of claim 22, wherein said interface further includes a means for is allotting ownership of said interface to one of said hubs up to a predetermined amount of time.

21. An interface to transfer data between a memory controller hub and an input/output (I/O) hub of a chipset within a computer system, comprising:

a bi-directional data signal path and a pair of source synchronous strobe signals, said data signal path transmits data in packets via split transactions, said packets including a request packet and completion packet, said request packet including a transaction descriptor; and

a set of command signals including unidirectional arbitration signal, a bi-directional stop signal, a system reset signal, a common clock signal, and a voltage reference signal.

35. The interface of claim 21, wherein said interface provides a point-to-point connection between said first hub and said second hub, exclusive of an external bus connected directly to the point-to-point connection.