TRANSLATION LAYER PARTITIONED BETWEEN HOST AND CONTROLLER

• US 20140208004A1
• Filed: 10/23/2013
• Published: 07/24/2014
• Est. Priority Date: 01/22/2013
• Status: Active Grant

• Current Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Original Assignee: LSI Corporation (Broadcom, Inc.)
• Inventors: Cohen, Earl T., Puri, Sumit
• Granted Patent: US 9,329,991 B2
• Time in Patent Office: Days
• US Class Current: 711/103
• CPC Class Codes: G06F 12/0246 in block erasable memory, e.g. flash memory
• CPC Class Codes: G06F 12/121 using replacement algorithms
• CPC Class Codes: G06F 2212/401 Compressed data
• CPC Class Codes: G06F 2212/7201 Logical to physical mapping or translation of blocks or pages
• CPC Class Codes: G06F 3/064 Management of blocks
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

A method for using a partitioned flash transition layer is disclosed. Step (A) receives, at an apparatus from a host, a write command having first write data. Step (B) generates second write data by compressing the first write data in the apparatus. The second write data generally has a variable size. Step (C) stores the second write data at a physical location in a nonvolatile memory. The physical location is a next unwritten location. Step (D) returns, from the apparatus to the host in response to the write command, an indication of the physical location.

Claims

1. A method for using a partitioned flash transition layer, comprising the steps of:

(A) receiving, at an apparatus from a host, a write command having first write data;

(B) generating second write data by compressing said first write data in said apparatus, wherein said second write data has a variable size;

(C) storing said second write data at a physical location in a nonvolatile memory, wherein said physical location is a next unwritten location; and

(D) returning, from said apparatus to said host in response to said write command, an indication of said physical location.

2. The method according to claim 1, further comprising the step of:

partitioning a flash transition layer associated with said nonvolatile memory between said apparatus and said host by storing (i) said indication in said host and (ii) information associated with said variable size in said apparatus.

3. The method according to claim 1, further comprising the steps of:

receiving, at said apparatus from said host, a read command having said indication of said physical location; and

retrieving said second write data by reading a portion of said nonvolatile memory including said physical location in response to said indication.

4. The method according to claim 3, further comprising the steps of:

recreating said first write data by decompressing said second write data as retrieved from said nonvolatile memory; and

returning said first write data as recreated to said host.

5. The method according to claim 1, wherein said write command further comprises an identifier of said first write data, the method further comprising the step of:

storing said identifier in said nonvolatile memory as at least a portion of a header associated with said second write data.

6. The method according to claim 5, further comprising the step of:

maintaining in said host a map associating said identifier with said indication of said physical location.

7. The method according to claim 5, wherein (i) said identifier is a logical block address and (ii) said indication comprises a physical address in said nonvolatile memory of one of a plurality of read units, each of said read units comprises a respective portion of data and a respective error correction information that protects said respective portion of data.

8. The method according to claim 7, wherein (i) said nonvolatile memory has a plurality of pages, (ii) said physical address is in a first one of said pages, (iii) said first page includes a first number of said read units, (iv) a second one of said pages includes a second number of said read units and (v) said first number is different from said second number.

9. The method according to claim 1, wherein said next unwritten location adjoins previously written data in a physical address space of said nonvolatile memory.

10. A method for using a partitioned flash transition layer, comprising the steps of:

(A) receiving, at an apparatus from a host, a write command comprising write data that has a variable size;

(B) storing said write data at a physical location in a nonvolatile memory, wherein said physical location is a next unwritten location; and

(C) returning, from said apparatus to said host in response to said write command, an indication of said physical location.

11. The method according to claim 10, further comprising the steps of:

receiving, at said apparatus from said host, a read command having said indication of said physical location; and

retrieving said write data by reading a portion of said nonvolatile memory including said physical location in response to said indication.

12. The method according to claim 11, further comprising the step of:

returning said write data from said apparatus to said host.

13. The method according to claim 10, wherein said write command further comprises an identifier of said write data, the method further comprising the step of:

storing said identifier in said nonvolatile memory as at least a portion of a header associated with said write data.

14. The method according to claim 13, further comprising the step of:

maintaining in said host a map associating said identifier with said indication of said physical location.

15. The method according to claim 13, wherein (i) said identifier is a logical block address and (ii) said indication comprises a physical address in said nonvolatile memory of one of a plurality of read units, each of said read units comprises a respective portion of data and a respective error correction information that protects said respective portion of data.

16. The method according to claim 15, wherein (i) said nonvolatile memory has a plurality of pages, (ii) said physical address is in a first one of said pages, (iii) said first page includes a first number of said read units, (iv) a second one of said pages includes a second number of said read units and (v) said first number is different from said second number.

17. The method according to claim 10, wherein said next unwritten location adjoins previously written data in a physical address space of said nonvolatile memory.

18. An apparatus comprising:

a nonvolatile memory; and

a circuit configured to (i) receive from a host a write command having first write data, (ii) generate second write data by compressing said first write data, (iii) store said second write data at a physical location in said nonvolatile memory, and (iv) return to said host an indication of said physical location in response to said write command, wherein (a) said second write data has a variable size and (b) said physical location is a next unwritten location.

19. The apparatus according to claim 18, wherein said apparatus is implemented as one or more integrated circuits.