Buffered memory module supporting two independent memory channels

• US 7,818,497 B2
• Filed: 08/31/2007
• Issued: 10/19/2010
• Est. Priority Date: 08/31/2007
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Gower, Kevin C., Maule, Warren E.
• Primary Examiner(s): Kim; Matt
• Assistant Examiner(s): PATEL, KAUSHIKKUMAR M
• Application Number:
  US11/848,322
• Publication Number:
  US 20090063761A1
• Time in Patent Office: 1,145 Days
• Field of Search: None
• US Class Current: 711/105
• CPC Class Codes: G06F 13/1668 Details of memory controller

Abstract

A memory system is provided that enhances the memory bandwidth available through a memory module. The memory system includes a memory controller and a memory module coupled to the memory controller. In the memory system, the memory controller is coupled to the memory module via at least two independent memory channels. In the memory system, the at least two independent memory channels are coupled to one or more memory hub devices of the memory module.

Claims

1. A memory system, comprising:

a memory controller; and

a memory module coupled to the memory controller, wherein the memory controller is coupled to the memory module via at least two independent memory channels, and wherein the at least two independent memory channels are coupled to one or more memory hub devices of the memory module, wherein the memory module comprises a single memory hub device, wherein both of the at least two independent memory channels are coupled to the single memory hub device of the memory module, wherein the single memory hub device comprises four separate memory device data interfaces for communicating with four separate sets of memory devices, wherein a first memory channel of the at least two independent memory channels is coupled to a first memory device data interface and a second memory device data interface, and wherein a second memory channel of the at least two independent memory channels is coupled to a third memory device data interface and a fourth memory device data interface.

2. The memory system of claim 1, wherein the memory module is one of a dual in-line memory module (DIMM) or a single in-line memory module (SIMM).

3. The memory system of claim 1, wherein the memory module comprises two memory hub devices, and wherein the first memory channel of the two independent memory channels is coupled to a first memory hub device of the two memory hub devices and the second memory channel of the two independent memory channels is coupled to a second memory hub device of the two memory hub devices.

4. The memory system of claim 3, wherein the first memory hub device comprises a first set of separate memory device data interfaces, each memory device data interface of the first set of separate memory device data interfaces providing a communication connection to a first separate set of memory devices, and wherein the second memory hub device, comprises a second set of separate memory device data interfaces, each memory device data interface of the second set of separate memory device data interfaces providing a communication connection to a second separate set of memory devices.

5. The memory system of claim 1, wherein:

the first memory device data interface is integrated in the single memory hub device, the first memory device data interface providing a communication interface to communicate with a first set of memory devices;

the second memory device data interface is integrated in the single memory hub device, the second memory device data interface providing a communication interface to communicate with a second set of memory devices;

the third memory device data interface is integrated in the single memory hub device, the third memory device data interface providing a communication interface to communicate with a third set of memory devices; and

the fourth memory device data interface is integrated in the single memory hub device, the fourth memory device data interface providing a communication interface to communicate with a fourth set of memory devices, wherein the first set of memory devices, the second set of memory devices, the third set of memory devices, and the fourth set of memory devices are separate from each other, and wherein the first, second, third, and fourth set of memory devices are communicated with by the single memory hub device via the separate first, second, third, and fourth memory device data interfaces.

6. The memory system of claim 1, wherein access requests are processed via the four separate memory device data interfaces in parallel.

7. The memory system of claim 1, wherein the memory system is a main memory of a data processing device.

8. A data processing system, comprising:

a processor; and

a memory controller coupled to the to the processor;

a memory module coupled to the memory controller wherein the memory controller is coupled to the memory module via at least two independent memory channels, and wherein the at least two independent memory channels are coupled to one or more memory hub devices of the memory module, wherein the memory module comprises a single memory hub device wherein both of the at east two independent memory channels are coupled to the single memory hub device of the memory module, wherein the single memory hub device comprises four separate memory device data interfaces for communicating with four separate sets of memory devices, wherein a first memory channel of the at least two independent memory channels is coupled to a first memory device data interface and a second memory device data interface, and wherein a second memory channel of the at least two independent memory channels is coupled to a third memory device data interface and a fourth memory device data interface.

9. The data processing system of claim 8, wherein the memory module is one of a dual in-line memory module (DIMM) or a single in-line memory module (SIMM).

10. The data processing system of claim 8, wherein the memory module comprises two memory hub devices, and wherein the first memory channel of the two independent memory channels is coupled to a first memory hub device of the two memory hub devices and the second memory channel of the two independent memory channels is coupled to a second memory hub device of the two memory hub devices.

11. The data processing system of claim 10, wherein the first memory hub device comprises a first set of separate memory device data interfaces, each memory device data interface of the first set of separate memory device data interfaces providing a communication connection to a first separate set of memory devices, and wherein the second memory hub device comprises a second set of separate memory device data interfaces, each memory device data interface of the second set of separate memory device data interfaces providing a communication connection to a second separate set of memory devices.

12. The data processing system of claim 8, wherein:

the first memory device data interface is integrated in the single memory hub device, the first memory device data interface providing a communication interface to communicate with a first set of memory devices;

the second memory device data interface is integrated in the single memory hub device, the second memory device data interface providing a communication interface to communicate with a second set of memory devices;

the third memory device data interface is integrated in the single memory hub device, the third memory device data interface providing a communication interface to communicate with a third set of memory devices; and

the fourth memory device data interface is integrated in the single memory hub device, the fourth memory device data interface providing a communication interface to communicate with a fourth set of memory devices, wherein the first set of memory devices, the second set of memory devices, the third set of memory devices, and the fourth set of memory devices are separate from each other, and wherein the first, second, third, and fourth set of memory devices are communicated with by the single memory hub device via the separate first, second, third, and fourth memory device data interfaces.

13. The data processing system of claim 8, wherein access requests are processed via the four separate memory device data interfaces in parallel.

14. A method of accessing memory devices of a memory module, comprising:

receiving, in one or more memory hub devices integrated in the memory module, an access request for accessing a portion of one of a first set of memory devices or a second set of memory devices integrated in the memory module, wherein the access request is received from a memory controller coupled to the memory module, wherein the memory controller is coupled to the memory module via at least two independent memory channels, and wherein the at least two independent memory channels are coupled to the one or more memory hub devices of the memory module, wherein the memory module comprises a single memory hub device, wherein both of the at least two independent memory channles are coupled to the single memory hub device of the memory module wherein the single memory hub device comprises four separate memory device data interfaces for communicating with four separate sets of memory devices, wherein a first memory channel of the at least two independent memory channels is coupled to a first memory device data interface and a second memory device data interface, and wherein a second memory channel of the at least two independent memory channels is coupled to a third memory device data interface and a fourth memory device data interface;

selecting one of the first memory device, data interface, the second memory device data interface, the third memory device data interface, or the fourth memory device data interface integrated in the single memory hub device, for performance of the access request; and

accessing one of four separate sets of memory devices in the memory module based on the selected first memory device data interface, the second memory device data interface, the third memory device data interface, or the fourth memory device data interface.

15. The method of claim 14, wherein the memory module is one of a dual in-line memory module (DIMM) or a single in-line memory module (SIMM).

16. The method of claim 14, wherein the memory module comprises two memory hub devices, and wherein the first memory channel of the two independent memory channels is coupled to a first memory hub device of the two memory hub devices and the second memory channel of the two independent memory channels is coupled to a second memory hub device of the two memory hub devices.

17. The method of claim 16, wherein the first memory hub device comprises a first set of separate memory device data interfaces, each memory device data interface of the first set of separate memory device data interfaces providing a communication connection to a first separate set of memory devices, and wherein the second memory hub device comprises a second set of separate memory device data interfaces, each memory device data interface of the second set of separate memory device data interfaces providing a communication connection to a second separate set of memory devices.

18. The method of claim 14, wherein:

the first memory device data interface is integrated in the single memory hub device, the first memory device data interface providing a communication interface to communicate with a first set of memory devices;

the second memory device data interface is integrated in the single memory hub device, the second memory device data interface providing a communication interface to communicate with a second set of memory devices;

the third memory device data interface is integrated in the single memory hub device, the third memory device data interface providing a communication interface to communicate with a third set of memory devices; and

the fourth memory device data interface is integrated in the single memory hub device, the fourth memory device data interface providing a communication interface to communicate with a fourth set of memory devices, wherein the first set of memory devices, the second set of memory devices, the third set of memory devices, and the fourth set of memory devices are separate from each other, and wherein the first, second, third, and fourth set of memory devices are communicated with by the single memory hub device via the separate first, second, third, and fourth memory device data interfaces.

19. The method of claim 14, wherein access requests are processed via the four separate memory device data interfaces in parallel.