Method and apparatus for queuing memory access commands in a memory queue of an information handling system

• US 20080091881A1
• Filed: 10/13/2006
• Published: 04/17/2008
• Est. Priority Date: 10/13/2006
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Brittain, Mark Andrew, Maule, Warren Edward, Retter, Eric Eugene
• Granted Patent: US 7,493,456 B2
• Time in Patent Office: Days
• US Class Current: 711/125
• CPC Class Codes: G06F 13/1642 with request queuing

Abstract

A memory controller includes an address queue with address queue locations that may expand to store address commands that point to consecutive locations in memory. In this manner, multiple address commands may combine together in a common expanded address queue location. In one embodiment, each address queue location includes a main information portion and a supplemental information portion. The supplemental information portion is smaller than the main information portion. The main information portion stores the target address information of a first address command. When the address queue receives an address command with a target address that is consecutive to the target address of the first command, then the supplemental address portion stores a subset of the target address of the second command.

Claims

1. A method of accessing information in a memory, the method comprising:

providing an address queue including a plurality of queue entry locations, each queue entry location including a main information location and a supplemental information location;

testing, by a queue controller, first and second memory access commands to determine if the first and second memory access commands refer to consecutive memory locations in a memory;

storing the first memory access command and a portion of the second memory access command in the same queue entry location of the memory queue if the testing step determines that the first and second memory access commands refer to consecutive memory locations in the memory; and

storing the first memory access command and the second memory access command in different queue entry locations, respectively, of the memory queue if the testing step determines that first and second memory access commands do not refer to consecutive memory locations in the memory.

2. The method of claim 1, wherein the supplemental information locations of the queue entry locations store fewer bits than the main information locations of the queue entry locations.

3. The method of claim 1, wherein the first storing step comprises:

storing the first memory access command in the main information location of a particular queue entry location; and

storing the second memory access command in the supplemental information location of the particular entry location if the testing step determines that the first and second memory access commands refer to consecutive memory locations in a memory.

4. The method of claim 1, wherein the second storing step comprises:

storing the first memory access command in the main information location of a particular queue entry location; and

storing the second memory access command in another queue entry location of the address queue if the testing step determines that the first and second memory access commands do not refer to consecutive memory locations in a memory.

5. The method of claim 1, wherein the main information locations of the queue entry locations in the address queue are each capable of storing a full target address of respective memory access commands, and the supplemental information locations of the address queue are each capable of storing a subset of the target address.

6. A method of accessing information in a memory, the method comprising:

providing an address queue including a plurality of queue entry locations, each queue entry location including a main information location and a supplemental information location;

receiving, by a queue controller, a plurality of memory access commands including a new memory access command that refers to a target address;

storing, by the queue controller, a subset of the target address of the new memory access command in the supplemental information location of a particular queue entry location if the subset corresponds to the target address of another memory access command stored in the main information location of the particular queue entry location; and

otherwise storing, by the queue controller, the full target address of the new memory access command in a main information location of a queue entry location other than the particular queue entry location.

7. The method of claim 6, wherein the supplemental information locations of the queue entry locations store fewer bits than the main information locations thereof.

8. The method of claim 6, wherein the first storing step further comprises comparing a non-column address portion of the target address of the new memory access command and non-column address portions of target addresses stored in the main information locations of the queue entry locations of the address queue.

9. The method of claim 6, wherein the memory access commands include memory write commands.

10. The method of claim 6, wherein the memory access commands include memory read commands.

11. A memory controller, comprising:

a queue controller that receives a plurality of memory access commands including a new memory access command that refers to a target address;

an address queue, coupled to the queue controller, including a plurality of queue entry locations, each queue entry location including a main information location and a supplemental information location;

wherein the queue controller stores a subset of the target address of the new memory access command in the supplemental information location of a particular queue entry location if the subset corresponds to the target address of another memory access command stored in the main information location of the particular queue entry location, and wherein otherwise the queue controller stores the full target address of the new memory access command in a main information location of a queue entry location other than the particular queue entry location.

12. The memory controller of claim 11, wherein the address queue is configured such that the supplemental information locations of the queue entry locations store fewer bits than the main information locations thereof.

13. The memory controller of claim 11, wherein the queue controller includes a group of comparators that compare a non-column address portion of the target address of the new memory access command and non-column address portions of target addresses stored in the main information locations of the queue entry locations of the address queue.

14. The memory controller of claim 11, wherein the memory access commands include memory write commands.

15. The memory controller of claim 11, wherein the memory access commands include memory read commands.

16. An information handling system (IHS) comprising:

a processor;

a memory; and

a memory controller coupled to the processor and the memory to control memory operations of the memory, the memory controller including;

a queue controller that receives a plurality of memory access commands including a new memory access command that refers to a target address;

an address queue, coupled to the queue controller, including a plurality of queue entry locations, each queue entry location including a main information location and a supplemental information location;

wherein the queue controller stores a subset of the target address of the new memory access command in the supplemental information location of a particular queue entry location if the subset corresponds to the target address of another memory access command stored in the main information location of the particular queue entry location, and wherein otherwise the queue controller stores the full target address of the new memory access command in a main information location of a queue entry location other than the particular queue entry location.

17. The IHS of claim 16, wherein the address queue is configured such that the supplemental information locations of the queue entry locations store fewer bits than the main information locations thereof.

18. The IHS of claim 16, wherein the queue controller includes a group of comparators that compare a non-column address portion of the target address of the new memory access command and non-column address portions of target addresses stored in the main information locations of the queue entry locations of the address queue.

19. The IHS of claim 16, wherein the memory access commands include memory write commands and memory read commands.

20. The IHS of claim 16, wherein the memory is one of volatile memory and non-volatile memory.