Method and system for supporting multiple cache configurations

• US 6,760,272 B2
• Filed: 12/07/2000
• Issued: 07/06/2004
• Est. Priority Date: 12/07/2000
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Franz, Keenan W., Vaden, Michael T.
• Primary Examiner(s): PEIKARI, BEHZAD
• Application Number:
  US09/731,869
• Publication Number:
  US 20020112120A1
• Time in Patent Office: 1,307 Days
• Field of Search: 365/230.05, 365/189.01, 365/189.04, 711/104, 711/1
• US Class Current: 365/230.05
• CPC Class Codes: G06F 12/0802 Addressing of a memory level in which the access to the desired data or data block requires associative addressing means, e.g. caches
• CPC Class Codes: G06F 2212/601 Reconfiguration of cache memory
• CPC Class Codes: G11C 2207/104 Embedded memory devices, e.g. memories with a processing device on the same die or ASIC memory designs
• CPC Class Codes: G11C 2207/2245 Memory devices with an internal cache buffer

Abstract

A processor card for supporting multiple cache configurations, and a microprocessor for selecting one of the multiple cache configurations is disclosed. The processor card has a first static random access memory mounted on a front side thereof and a second static random access memory mounted on a rear side thereof. The address pins of the memories are aligned. Each pair of aligned address pins are electrically coupled to thereby concurrently receive an address bit signal from the microprocessor. During an initial boot of the microprocessor, the microprocessor includes a multiplexor for providing the address bit signals to the address pins in response to a control signal indicative of a selected cache configuration.

Claims

1. A device, comprising:

a processor card;

a first memory device mounted upon said processor card, said first memory device including a first address pin and a second address pin; and

a second memory device mounted upon said processor card, said second memory device including a third address pin and a fourth address pin, said first address pin and said third address pin being functionally equivalent address pins, said second address pin and said fourth address pin being functionally equivalent address pins,

wherein said first address pin and said fourth address pin are electrically coupled to thereby concurrently receive a first address bit signal, and

wherein said second address pin and said third address pin are electrically coupled to thereby concurrently receive a second address bit signal.

2. The device of claim 1, wherein

said first memory device is mounted to a front side of said processor card; and

said second memory device is mounted to a rear side of said processor card.

3. The device of claim 2, wherein

said first address pin and said fourth address pin are aligned;

and

said second address pin and said third address pin are aligned.

4. The device of claim 1, wherein

said first memory device is a static random access memory;

and

said second memory device is a static random access memory.

5. The device of claim 1, wherein

said first memory device further includes a fifth address pin;

and

said second memory device further includes a sixth address pin, said fifth address pin and said sixth address pin being electrically coupled to thereby concurrently receive a third address bit signal.

6. The device of claim 5, wherein

said fifth address pin and said sixth address pin are functionally dissimilar address pins.

7. The device of claim 5, wherein

said first memory device further includes a seventh address pin;

and

said second memory device further includes an eighth address pin, said seventh address pin and said eighth address pins being electrically coupled to thereby concurrently receive a fourth address bit signal.

8. The device of claim 7, wherein

said fifth address pin and said eighth address pin are functionally equivalent address pins;

and

said sixth address pin and said seventh address pin are functionally equivalent address pins.

9. A system, comprising:

a first memory device including a first address pin and a second address pin;

a second memory device including a third address pin and a fourth address pin, said first address pin and said third address pin being functionally equivalent address pins, said second address pin and said fourth address pin being functionally equivalent address pins; and

a microprocessor operable to concurrently provide a first address bit signal to said first address pin and said fourth address pin, said microprocessor further operable to concurrently provide a second address bit signal to said second address pin and said third address pin.

10. The system of claim 9, further comprising:

a processor card having said first memory device and said second memory device mounted thereon.

11. The system of claim 10, wherein

said first memory device is mounted to a front side of said processor card;

and

said second memory device is mounted to a rear side of said processor card.

12. The system of claim 11, wherein

said first address pin and said fourth address pin are aligned;

and

said second address pin and said third address pin are aligned.

13. The system of claim 9, wherein

said first memory device is a static random access memory;

and

said second memory device is a static random access memory.

14. The system of claim 9, wherein

said first memory device further includes a fifth address pin;

said second memory device further includes a sixth address pin; and

said microprocessor is further operable to concurrently provide a third address bit signal to said fifth address pin and said sixth address pin.

15. The system of claim 14, wherein

said fifth address pin and said sixth address pin are functionally dissimilar address pins.

16. The system of claim 14, wherein

said first memory device further includes a seventh address pin;

said second memory device further includes an eighth address; and

said microprocessor is further operable to concurrently provide a fourth address bit signal to said seventh address pin and said eighth address pin.

17. The system of claim 16, wherein

said fifth address pin and said eighth address pin are functionally equivalent address pins;

and

said sixth address pin and said seventh address pin are functionally equivalent address pins.

18. The system of claim 16, wherein

said microprocessor includes a multiplexor operable to provide said first address bit signal, said second address bit signal, said third address bit signal, and said fourth address bit signal in response to a control signal indicative of a cache configuration corresponding to said first address bit signal, said second address bit signal, said third address bit signal, and said fourth address bit signal.

19. The system of claim 14, wherein

said microprocessor includes a multiplexor operable to provide said first address bit signal, said second address bit signal, and said third address bit signal in response to a control signal indicative of a cache configuration corresponding to said first address bit signal, said second address bit signal, and said third address bit signal.

20. The system of claim 9, wherein

said microprocessor includes a multiplexor operable to provide said first address bit signal and said second address bit signal in response to a control signal indicative of a cache configuration corresponding to said first address bit signal and said second address bit signal.

21. A method, comprising:

providing a processor board including a first conductor and a second conductor;

providing a first memory device including a first address pin and a second address pin;

providing a second memory device including a third address pin and a fourth address pin, said first address pin and said fourth address pin being functionally equivalent address pins, said second address pin and said third address pin being functionally equivalent address pin;

mounting said first memory device on said processor card, said first address pin contacting said first conductor, said second address pin contacting said second conductor;

mounting a second memory device said processor card, said third address pin contacting said first conductor whereby said first address pin and said third address pin are electrically coupled, said fourth address pin contacting said second conductor whereby said second address pin and said fourth address pin are electrically coupled.

22. The method of claim 21, wherein

said mounting of said first memory device on said processor card includes mounting first memory device said mounted on a front side of said processor card, and

said mounting of said second memory device on said processor card includes mounting said second memory device said mounted on a rear side of said processor card.

23. The method of claim 22, wherein

said mounting of said second memory device said on said processor card includes aligning said first address pin and said third address pin and aligning said second address pin and fourth address pin are aligned.