Method and apparatus for controlling memory client access to address ranges in a memory pool

• US 6,715,053 B1
• Filed: 10/30/2000
• Issued: 03/30/2004
• Est. Priority Date: 10/30/2000
• Status: Active Grant

• Current Assignee: ATI Technologies ULC (Advanced Micro Devices, Inc.)
• Original Assignee: ATI International SRL (Advanced Micro Devices, Inc.)
• Inventors: Grigor, Gordon F.
• Primary Examiner(s): Kim, Matthew
• Assistant Examiner(s): BATAILLE, PIERRE MICHE
• Application Number:
  US09/699,858
• Time in Patent Office: 1,247 Days
• Field of Search: 711/152, 711/153, 711/163, 711/170, 711/173, 711/133, 711/134, 345/533, 345/531, 345/541
• US Class Current: 711/170
• CPC Class Codes: G06F 12/0284 Multiple user address space allocation, e.g. using different base addresses interprocessor communication G06F15/163
• CPC Class Codes: G06F 12/1466 Key-lock mechanism

Abstract

An address access control system dynamically forms a plurality of address ranges in a predefined unified address structure during operation of a computer system. A plurality of memory clients is operatively connected to the unified address structure. A plurality of capabilities is also provided with respect to memory clients accessing address ranges. A memory controller is operatively connected to the plurality of memory clients and to the unified address structure. The memory controller dynamically structures an association of a respective range of the plurality of ranges with at least one respective capability of a plurality of capabilities for at least one memory client of the plurality of memory clients.

Claims

1. A method for processing a request in an address access control system having a plurality of address ranges in a predetermined unified address structure, a plurality of memory clients operatively connected to the unified address structure, and at least one table having a plurality of capabilities with respect to clients accessing address ranges, comprising the steps of:

dynamically structuring during normal operation an association of a respective range of the plurality of ranges with at least one respective capability of the plurality of capabilities for at least one client of the plurality of memory clients;

receiving a request from a respective client of the plurality of memory clients, the request being for a predetermined operation and a predetermined address in the unified address structure;

comparing the predetermined address of the request against all address ranges, and approving the request when the predetermined address is in an address range in which the respective client is associated with a capability which corresponds to the predetermined operation of the request;

servicing the request when the request ha been approved;

determining, when the request is not approved, if the predetermined operation of the request is a read request or a write request, and for a read request, servicing the request with bogus data, and for a write request, taking no action.

2. The method according to claim 1, wherein each address range of the plurality of address ranges has location and size identifiers.

3. The method according to claim 1, wherein each address range of the plurality of address ranges has a start address and a stop address.

4. The method according to claim 1, wherein each address range of the plurality of address ranges has a start address and a size identifier.

5. The method according to claim 1, wherein a respective capability of the plurality of capabilities is one of read only, write only, and read/write.

6. The method according to claim 1, wherein the respective range has associated therewith a number of clients, which is a subset of the plurality of memory clients.

7. The method according to claim 1, wherein address ranges in the unified address structure have at least one of the following structures:

at least two of the address ranges do not overlap one another;

at least two of the address ranges at least partially overlap one another; and

at least Two of the address ranges completely over lap one another.

8. The method according to claim 1, wherein address ranges are located in the unified address structure independent of one another.

9. The method according to claim 1, wherein a respective memory client of the plurality of memory clients is one of a command traffic processor client, 2D module client, 3D module client, host client, video capture client, and display client.

10. The method according to claim 1, wherein a respective memory client of the plurality of memory clients is one of a north bridge client and a processing unit client.

11. The method according to claim 1, wherein two respective memory clients of the plurality of memory clients are respectively a north bridge client and a processing unit client.

12. The method according to claim 1, wherein the system initially has a default configuration in which all clients have access to all addresses in the unified address structure and with all capabilities.

13. The method according to claim 12, wherein all capabilities include the capability of a client to read data from any address or range of addresses in the unified address structure, and to write data to any address or range of addresses in the unified address structure.