Direct mapped repair cache systems and methods

• US 20060077734A1
• Filed: 09/20/2005
• Published: 04/13/2006
• Est. Priority Date: 09/30/2004
• Status: Abandoned Application

• Current Assignee: Avago Technologies General IP PTE Limited (Broadcom, Inc.)
• Original Assignee: Avago Technologies General IP PTE Limited (Broadcom, Inc.)
• Inventors: Fong, John Y.
• Application Number:
  US11/230,405
• Publication Number:
  US 20060077734A1
• Time in Patent Office: Days
• US Class Current: 365/200
• CPC Class Codes: G11C 29/76 using address translation or modifications
• CPC Class Codes: G11C 29/808 using a flexible replacement scheme

Abstract

The present invention facilitates memory devices and operation thereof by employing a repair cache system 600 to correct or repair identified faulty memory locations. The repair cache system 600 includes a repair verification router that compares a memory address 604 for a read/write request to a list or series of repair locations 608. On identifying a matching repair location, a repair register 616 located within a repair register bank 615 is coupled to a data bus 626. Otherwise, a memory location within the main memory 630 and addressed by the memory address 604 is coupled to the data bus 626.

Claims

1. A repair cache system comprising:

a main memory comprising identified valid memory locations and identified faulty memory locations;

a repair component comprising repair registers associated with the faulty memory locations; and

a repair verification router comprising repair locations associated with the faulty memory locations, wherein the repair verification router routes read/write requests for faulty memory locations to the repair component and routes read/write requests for identified valid memory locations to the main memory.

2. The system of claim 1, wherein the main memory is comprised of ferroelectric memory cells.

3. The system of claim 1, wherein the repair locations respectively comprise a repair address.

4. The system of claim 1, wherein the repair locations respectively comprise a repair address and a repair enable indicator.

5. The system of claim 3, wherein the repair addresses comprise memory addresses of identified faulty memory locations.

6. The system of claim 1, wherein the memory locations and the repair registers have a size of 16-bits.

7. The system of claim 1, wherein the memory locations have a size of 32-bits.

8. The system of claim 3, wherein the repair addresses and memory addresses of the memory locations have a size of 18 bits.

9. The system of claim 1, wherein the verification router further comprises a non-volatile memory for maintaining the repair locations.

10. The system of claim 9, wherein the verification router further comprises a comparator that compares a memory address of a read/write request to repair locations to identify a match that routes the read/write request to the repair component.

11. A direct mapped repair cache system comprising:

a repair verification component comprising a list of repair locations and a list or comparators;

a repair register bank comprising a list of repair registers;

a main memory comprising identified valid memory locations and identified faulty memory locations;

a data bus selectively coupled to the repair register bank and the main memory; and

wherein the repair verification component compares a memory address of a read/write request to the list of repair locations with the list of comparators to identify a match, couples a matching repair register of the repair register bank to the data bus on identifying a match, and couples the main memory to the data bus on not identifying a match.

12. The system of claim 11, wherein the repair registers respectively comprise a repair address equal to a memory address of associated memory locations.

13. The system of claim 11, wherein the repair registers respectively comprise a repair address and a repair enable indicator, wherein the repair enable indicator is set to valid on the repair address being a memory address of a faulty memory location.

14. The system of claim 11, wherein the list of comparators identify a match by comparing repair addresses of the list of repair locations with memory address in parallel.

15. A method of operating a direct mapped repair cache comprising:

receiving a request for read/write access to a memory address;

comparing the memory address to a list of repair locations to identify a matching and valid repair location;

on failure to identify a matching and valid repair location, providing read/write access to a memory location in main memory addressed by the memory address; and

on identifying a matching and valid repair location, preventing read/write access to main memory and providing read/write access to a repair register associated with the matching and valid repair location.

16. The method of claim 15, comparing the memory address to the list of repair locations comprising performing a bitwise comparison of the memory address to repair addresses of the list of repair locations.

17. The method of claim 15, wherein the matching and valid repair location has a repair enable indicator set to valid.

18. The method of claim 15, wherein providing read/write access to the repair register comprises coupling a data bus to the repair register.

19. A method of configuring a repair cache system comprising:

providing a memory array comprising memory locations;

testing the memory array to identify faulty memory locations and identify valid memory locations; and

associating repair registers and repair locations to the identified faulty memory locations, wherein the repair registers are individually associated to the repair locations.

20. The method of claim 19, wherein associating the repair registers and repair locations to the identified faulty memory locations comprises setting repair addresses of the repair locations to memory addresses of the identified faulty memory locations.

21. The method of claim 19, further comprising setting repair enable indicators of the associated repair registers to valid.

22. The method of claim 19, wherein the associated repair locations are a subset of possible repair locations.