System and method for optimizing interconnections of memory devices in a multichip module

• US 7,836,252 B2
• Filed: 08/29/2002
• Issued: 11/16/2010
• Est. Priority Date: 08/29/2002
• Status: Active Grant

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Ryan, Kevin J.
• Primary Examiner(s): TSAI, SHENG JEN
• Application Number:
  US10/232,842
• Publication Number:
  US 20040044833A1
• Time in Patent Office: 3,001 Days
• Field of Search: 711/5, 711/115, 711/E12.081, 711/E12.1, 365/189
• US Class Current: 711/115
• CPC Class Codes: G11C 5/025 Geometric lay-out considerations of storage- and peripheral-blocks in a semiconductor storage device geometrical lay-out of the components in integrated circuits, H01L27/0207
• CPC Class Codes: G11C 5/04 Supports for storage elements , e.g. memory modules; Mounting or fixing of storage elements on such supports
• CPC Class Codes: G11C 5/063 Voltage and signal distribution in integrated semi-conductor memory access lines, e.g. word-line, bit-line, cross-over resistance, propagation delay

Abstract

An apparatus and method couples memory devices in a memory module to a memory hub on the module such that signals traveling from the hub to the devices have the same propagation time regardless of which device is involved. The hub receives memory signals from a controller over a high speed data link which the hub translates into electrical data, command and address signals. These signals are applied to the memory devices over busses having equivalent path lengths. The busses may also be used by the memory devices to apply data signals to the memory hub. Such data signals can be converted by the memory hub into memory signals and applied to the controller over the high speed data link. In one example, the memory hub is located in the center of the memory module.

Claims

1. A plurality of memory modules coupled to a controller, each memory module comprising;

a substrate having an outer perimeter;

a memory hub on the substrate, each memory hub for each respective memory module coupled to the controller by a respective memory link, each memory hub operable to receive memory signals from and apply memory signals to its respective memory link, each memory hub being directly coupled to a respective memory hub of another memory module by a hub communication link, each hub communication link operable to transmit memory signals between its two respectively coupled memory hubs; and

a plurality of memory devices arranged on the substrate, all of the memory devices arranged on the substrate being substantially equidistant from the outer perimeter of the memory hub and electrically coupled directly to the memory hub.

2. The plurality of memory modules of claim 1 wherein each of the memory links comprises at least one of a control bus operable to transmit command signals, a address bus operable to transmit address signals, or a data bus operable to transmit data signals.

3. The plurality of memory modules of claim 2 wherein each of the memory links further comprises at least one point-to-point link.

4. The plurality of memory modules of claim 3 wherein any of the busses and point-to-point links may be multiplexed.

5. The plurality of memory modules of claim 1 wherein each of the memory links comprises at least one point-to-point link.

6. The plurality of memory modules of claim 1 wherein each of the memory links comprises at least one unidirectional link operable to transmit at least one of command, address and write data signals from a controller to the memory hub.

7. The plurality of memory modules of claim 1 wherein each of the memory links comprises at least one unidirectional link operable to transmit at least one of command and read data signals from the memory hub to the controller.

8. The plurality of memory modules of claim 1, wherein the memory signals comprise at least one of command, address and data signals.

9. The plurality of memory modules of claim 1 wherein each of the memory link comprises an optical bus and the memory signals are optical signals, and further wherein each memory hub includes at least one optical transmitter operable to send memory signals and at least one optical receiver operable to receive memory signals, each memory hub being further operable to translate between the optical memory signals and the electrical command, address and data signals.

10. The plurality of memory modules of claim 9 wherein each of the memory links comprises a fiber optic link.

11. The plurality of memory modules of claim 9 wherein each of the memory links comprises free space.

12. The plurality of memory modules of claim 9 wherein each of the memory modules is a DIMM.

13. The plurality of memory modules of claim 9 wherein the plurality of memory devices comprise DRAM devices.

14. The plurality of memory modules of claim 9 wherein each memory device is electrically coupled to the memory hub by a control bus, an address bus and a data bus.

15. The plurality of memory modules of claim 9 wherein the memory hub applies the command, address and data signals to each memory device simultaneously.

16. The plurality of memory modules of claim 9 wherein the memory hub detects address information in a memory signal and applies command, address and data signals to a corresponding memory device.

17. The plurality of memory modules of claim 9 wherein the memory hub is positioned at a center of the module.

18. A computer system, comprising:

a data input device;

a data output device;

a processor coupled to the data input and data output devices;

a controller electrically coupled to the processor, the controller being operable to receive and transmit memory signals on a plurality of memory links; and

a plurality of memory modules, each memory module comprising;

a substrate;

a memory hub coupled to a respective one of the memory links, each memory hub having electrical output ports for sending and receiving electrical signals, each memory hub being operable to translate received electrical signals to corresponding memory signals to be applied to its respective memory link and translate memory signals into corresponding electrical signals to be applied at the output ports, each memory hub directly coupled to a respective memory hub of another memory module by a hub communication link, each hub communication link operable to transmit memory signals between its two respectively coupled memory hubs; and

a plurality of memory devices arranged on the substrate, with all of the memory devices arranged on the substrate located substantially equidistant from the memory hub and electrically coupled directly to a respective output port of the memory hub to receive command, address and data signals from the memory hub and to provide data signals to the memory hub.

19. The computer system of claim 18 wherein each of the memory links comprises at least one of a control bus operable to transmit command signals, a address bus operable to transmit address signals and a data bus operable to transmit data signals.

20. The computer system of claim 19 wherein each of the memory links further comprises at least one point-to-point link.

21. The computer system of claim 20 wherein any of the busses and point-to-point links may be multiplexed.

22. The computer system of claim 18 wherein each of the memory links comprises at least one point-to-point link.

23. The computer system of claim 18 wherein each of the memory links comprises at least one unidirectional link operable to transmit at least one of command, address and write data signals from the controller to the respectively coupled memory hub.

24. The computer system of claim 19 wherein each of the memory links comprises at least one unidirectional link operable to transmit at least one of command and read data signals from the respective memory hub to the controller.

25. The computer system of claim 19 wherein the memory signals comprise at least one of command, address and data signals.

26. The computer system of claim 18 wherein each of the memory links comprises an optical bus, and further wherein each memory hub includes at least one optical transmitter operable to send memory signals and at least one optical receiver operable to receive memory signals, each memory hub being further operable to translate between the optical memory signals and the electrical signals;

and further wherein the controller is operable to receive electrical signals from the processor and generate corresponding memory signals with at least one optical transmitter, the controller being further operable to receive memory signals with at least one optical receiver and generate corresponding electrical signals.

27. The computer system of claim 26 wherein each of the memory links comprises a fiber optic link.

28. The computer system of claim 26 wherein each of the memory links comprises free space.

29. The computer system of claim 26 wherein each memory module comprises a DIMM.

30. The computer system of claim 26 wherein the plurality of memory devices comprise DRAM devices.

31. The computer system of claim 26 wherein each memory device is electrically coupled to the memory hub through control, address bus and data busses.

32. The computer system of claim 26 wherein each respective memory hub applies command, address and data signals to each of its corresponding memory devices simultaneously.

33. The computer system of claim 26 wherein each memory hub detects address information in a memory signal and applies command, address and data signals to a corresponding memory device.

34. The module of claim 26 wherein each memory hub is positioned at a center of its respective module.