Memory device and method of controlling the same

• US 8,843,696 B2
• Filed: 03/22/2012
• Issued: 09/23/2014
• Est. Priority Date: 09/21/2011
• Status: Active Grant

• Current Assignee: Kioxia Corporation
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Hasegawa, Misao
• Primary Examiner(s): Rojas, Midys
• Application Number:
  US13/427,252
• Publication Number:
  US 20130073795A1
• Time in Patent Office: 915 Days
• Field of Search: 711/100, 711/103, 711/115, 711/154, 711/170, 711/173, 711/E12.001
• US Class Current: 711/103
• CPC Class Codes: G06F 12/0238 Memory management in non-volatile memory, e.g. resistive RAM or ferroelectric memory
• CPC Class Codes: G06F 12/0246 in block erasable memory, e.g. flash memory
• CPC Class Codes: G06F 13/16 for access to memory bus G06F13/28 takes precedence
• CPC Class Codes: G06F 13/4243 with synchronous protocol
• CPC Class Codes: G06F 3/0679 Non-volatile semiconductor memory device, e.g. flash memory, one time programmable memory [OTP]
• CPC Class Codes: G06F 3/0688 Non-volatile semiconductor memory arrays
• CPC Class Codes: G11C 16/00 Erasable programmable read-only memories G11C14/00 takes precedence

Abstract

According to one embodiment, a memory device includes a nonvolatile memory in which data write or data read is executed in units of a plurality of cells, and a controller configured to control the memory and to manage a memory space of the memory by dividing the memory space into a plurality of partitions.

Claims

1. A memory device comprising:

a nonvolatile memory in which data write or data read is executed in units of a plurality of cells; and

a controller configured to control the nonvolatile memory and to manage a memory space of the nonvolatile memory by dividing the memory space into at least a first partition and a second partition,

wherein the controller is configured to make the memory device receive a request for writing data to the first partition and a request for writing data to the second partition independently of each other,

the controller determines, when a request for writing data has been received, whether to divide a data size of write data associated with the request, into the units of the plurality of cells,

the controller divides the data size of write data when the controller determines to divide the data size of write data, and

the controller issues a request for transmitting write data to the second partition and receive the write data for the second partition, during a period in which data writing to the first partition is being executed.

2. The device of claim 1, wherein the controller is configured to execute data read from the nonvolatile memory by dividing a data size of read data, when a data read request has been received.

3. The device of claim 1, wherein when the controller determines that division of the data size is unnecessary, the controller is configured to execute data write or data read in units of the plurality of cells, with the data size of the write data or read data being maximized.

4. The device of claim 1, wherein a unit of division of the data size is a unit of the plurality of cells by which the data write or data read is executed.

5. The device of claim 1, wherein as a criterion for the controller to determine whether division of the data size is necessary or not, the controller determines that the division of the data size is necessary when the following two conditions are satisfied:

(1) a data write request or a data read request for at least the first partition and the second partition is issued; and

(2) a data size of the data write request or the data read request is the unit of the plurality of cells or more.

6. The device of claim 1, wherein as a criterion for the controller to determine whether division of the data size is necessary or not, the controller determines that the division of the data size is necessary when the following three conditions are satisfied:

(1) a data write request or a data read request for at least the first partition or the second partition is issued;

(2) a least one or more query requests are issued; and

(3) a data size of the data write request or the data read request is the unit of the plurality of cells or more, wherein the query requests are mainly used to acquire information of the memory device.

7. The device of claim 1, wherein when the first partition has a higher priority than the second partition, the controller is configured not to divide the data size of the write data and to execute data write of the first partition.

8. The device of claim 1, wherein the memory device is a memory device based on Universal Flash Storage (UFS).

9. A method of controlling a memory device including a nonvolatile memory in which data write or data read is executed in units of a plurality of cells, a memory space of the nonvolatile memory being divided into at least a first partition and a second partition, the method comprising:

receiving a request for writing data to the first partition and a request for writing data to the second partition independently of each other,

determining, when a request for writing data has been received, whether to divide a data size of write data associated with the request, into the units of the plurality of cells,

dividing the data size of write data when the data size of write data is determined to divide; and

issuing a request for transmitting write data to the second partition and receiving the write data for the second partition during a period in which data writing to the first partition is being executed.

10. The method of claim 9, further comprising executing data read from the nonvolatile memory by dividing a data size of read data, when a data read request has been issued.

11. The method of claim 9, further comprising executing, when division of the data size is unnecessary, data write or data read in units of the plurality of cells, with the data size of the write data or read data being maximized.

12. The method of claim 9, wherein a unit of division of the data size is a unit of the plurality of cells by which the data write or data read is executed.

13. The method of claim 9, wherein as a criterion for determining whether division of the data size is necessary or not, it is determined that the division of the data size is necessary when the following two conditions are satisfied:

(1) a data write request or a data read request for at least the first partition and the second partition is issued; and

(2) a data size of the data write request or the data read request is the unit of the plurality of cells or more.

14. The method of claim 9, wherein as a criterion for determining whether division of the data size is necessary or not, it is determined that the division of the data size is necessary when the following three conditions are satisfied:

(1) a data write request or a data read request for at least the first partition or the second partition is issued;

(2) a least one or more query requests are issued; and

(3) a data size of the data write request or the data read request is the unit of the plurality of cells or more, wherein the query requests are mainly used to acquire information of the memory device.

15. The method of claim 9, further comprising, when the first partition has a higher priority than the second partition, executing no division of the data size of the write data, and executing data write of the first partition.

16. The method of claim 9, wherein the memory device is a memory device based on Universal Flash Storage (UFS).