Granted Patent B2

US 7,739,452 · App. 12/400,437 · Granted Jun 15, 2010

Abstract

Claims (61)

1. A method, comprising:

receiving a memory read having a first associated sequence number;

receiving a memory write having a second associated sequence number;

determining that a memory conflict exists based on the first associated sequence number and the second associated sequence number; and

responsively restarting processing of data associated with the first associated sequence number.

2. The method of claim 1 , wherein receiving the memory read comprises:

recording a first address and the first associated sequence number in a read table;

searching a write table for a matching entry with an address matching the first address and a sequence number that is less than or equal to the first associated sequence number; and

responsive to finding the matching entry in the write table, retrieving data from the write table.

3. The method of claim 2 , further comprising:

responsive to not finding the matching entry in the write table, sending the memory read to a memory system.

4. The method of claim 2 , wherein receiving the memory write comprises:

recording a second address, the second associated sequence number, and write data in the write table.

5. The method of claim 4 , wherein determining that the memory conflict exists comprises:

searching the read table for an address matching the second address and a sequence number that is greater than the second associated sequence number.

6. The method of claim 5 , further comprising:

receiving a start command with a third associated sequence number; and

receiving a done command with a fourth associated sequence number.

7. The method of claim 6 , further comprising:

sending write data to a memory system upon receipt of the done command; and

responsively flushing the entries in the read table and the write table corresponding to the fourth associated sequence number.

8. The method of claim 1 , further comprising:

determining a prediction of the memory conflict; and

responsively applying a stall to a memory system.

9. The method of claim 8 , wherein determining the prediction of the memory conflict comprises:

receiving one or more memory reads;

determining one or more read addresses associated with the one or more memory reads;

receiving one or more memory writes;

determining one or more write addresses associated with the one or more memory writes; and

determining the prediction based on the one or more read addresses and the one or more write addresses.

10. The method of claim 8 , wherein the prediction comprises predicting a memory write; and

wherein responsively applying the stall comprises delaying at least one memory read until the predicted memory write occurs.

11. An controller, comprising:

means for receiving a memory read having a first associated sequence number;

means for receiving a memory write having a second associated sequence number;

means for determining that a memory conflict exists based on the first associated sequence number and the second associated sequence number; and

means for restarting processing of data associated with the first associated sequence number based on the determined memory conflict.

12. The controller of claim 11 , wherein the means for receiving the memory read comprise:

means for recording a first address and the first associated sequence number in a read table;

means for searching a write table for a matching entry with an address matching the first address and a sequence number less than or equal to the first associated sequence number; and

means for retrieving data from the write table, responsive to finding the matching entry in the write table.

13. The controller of claim 12 , further comprising:

means for sending the memory read to a memory system, responsive to not finding the matching entry in the write table.

14. The controller of claim 12 , wherein the means for receiving the memory write comprise:

means for recording a second address, the second associated sequence number, and write data in the write table.

15. The controller of claim 14 , wherein the means for determining that the memory conflict exists comprise:

means for searching the read table for an address that matches the second address and a sequence number that is greater than the second associated sequence number.

16. The controller of claim 15 , further comprising:

means for receiving a command, wherein the command is either a start command with a third associated sequence number, or a done command with a fourth associated sequence number.

17. The controller of claim 16 , further comprising:

means for sending write data to a memory system upon receipt of the done command; and

means for responsively flushing the entries in the read table and the write table corresponding to the fourth associated sequence number.

18. The controller of claim 11 , further comprising:

means for determining a prediction of the memory conflict; and

means for applying a stall to a memory system in response to predicting the memory conflict.

19. The controller of claim 18 , wherein the means for determining the prediction of the memory conflict comprise:

means for receiving one or more memory reads, each of the one or more memory reads comprising one or more read addresses;

means for receiving one or more memory writes, each of the one or more memory writes comprising one or more write addresses; and

means for determining the prediction based on the one or more read addresses and the one or more write addresses.

20. The controller of claim 18 , wherein the prediction of the memory conflict comprises predicting a memory write; and

wherein the means for applying the stall comprise means for delaying at least one memory read until the predicted memory write occurs.

Assignments (2)

Continuity (9)