Hybrid memory device for storing write data based on attribution of data stored therein

• US 9,804,801 B2
• Filed: 03/24/2015
• Issued: 10/31/2017
• Est. Priority Date: 03/26/2014
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd., SungKyunKwan University's Research & Business Foundation (SungKyunKwan University (SKKU))
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Moon, Sangkwon, Kim, Jin-Soo, Lee, Young-Sik, Jeong, Jinkyu, Kim, Kyung Ho
• Primary Examiner(s): Rossiter, Sean D
• Application Number:
  US14/667,242
• Publication Number:
  US 20150278104A1
• Time in Patent Office: 952 Days
• CPC Class Codes: G06F 3/0611 in relation to response time
• CPC Class Codes: G06F 3/065 Replication mechanisms
• CPC Class Codes: G06F 3/0656 Data buffering arrangements
• CPC Class Codes: G06F 3/068 Hybrid storage device

Abstract

A method of processing data in a memory system including a control unit and a hybrid memory device having a first memory and a second memory, includes; receiving first write data, storing the first write data in the first memory and assigning a first group state from among a plurality of group states to the stored first write data in response to first attribution information, completing a data processing operation in the memory system directed to the stored first write data that changes the attribution information associated with the stored first write data by monitoring of the first attribution information using an operating system running on the memory controller, and changing the first group state assigned to the stored first write data to a second group state from among the plurality of group states, the second group state having a different priority than a priority for the first group state.

Claims

1. A hybrid memory device comprising:

a first memory operating according to a first speed and configured for use as a primary memory to receive and store write data and assigned attribution information;

a second memory operating according to a second speed slower than the first speed of the first memory and providing greater data storage capacity than the first memory; and

a memory controller configured to;

perform a flush operation that secures additional free space in the first memory by copying data stored in the first memory to the second memory,

receive the attribution information associated with certain data from the host,

classify the data stored in the first memory into a plurality of group states based on the attribution information associated with the data to be stored in the first memory, wherein the plurality of group states range from a lowest priority to a highest priority,

upon receiving a write data request including the write data, determine whether sufficient free space exists in the first memory to store the write data, and upon determining that insufficient free space exists in the first memory, overwrite data assigned a lowest priority group state with the write data, and

change, in response to completing a process executed upon previous write data written into the first memory, attribution information assigned to the previous write data to reflect that space storing the previous write data within the first memory is free space that is available to be overwritten without copying the previous write data from the first memory to the second memory.

2. The hybrid memory device of claim 1, wherein the memory controller is further configured to execute the flush operation in response to determining that insufficient free space exists in the first memory.

3. The hybrid memory device of claim 1, wherein the memory controller is further configured to immediately write the write data into the first memory in response to determining that sufficient free space exists in the first memory.

4. The hybrid memory device of claim 1, wherein the plurality of group states comprises a highest priority group state, the lowest priority group state, a second highest priority group state, and a second lowest priority group state.

5. The hybrid memory device of claim 4, wherein the other data overwritten by the memory controller includes data that is assigned both the lowest priority group state and the second lowest priority group state.

6. The hybrid memory device of claim 4, wherein:

the memory controller is configured to reference an attribution information table, and

each data unit stored in the first memory has corresponding flag bits, within the attribution information table, indicating an assigned group state among the group states for the data unit.

7. The hybrid memory device of claim 6, wherein the memory controller is further configured to update the attribution information table in response to completion of the process.

8. The hybrid memory device of claim 1, wherein the memory controller is further configured to execute the flush operation in response to an externally-provided command.

9. The hybrid memory device of claim 1, wherein the memory controller is further configured to periodically execute the flush operation.

10. The hybrid memory device of claim 1, wherein the second speed is slower than the first speed.

11. The hybrid memory device of claim 1, wherein a first of the group states is a highest priority group state, a second of the group states is the lowest priority group state, and a third of the group states is an intermediate group state between the highest priority group state and lowest priority group state.

12. In a memory system including a control unit and a hybrid memory device, the hybrid memory device including a memory controller, a first memory operating according to a first speed and a second memory operating according to a second speed slower than the first speed of the first memory and providing greater data storage capacity than the first memory, a method of re-allocating memory space in the first memory during execution of a write operation comprises:

referencing an attribute information table listing respectively assigned group states for first data, second data and third data stored in the first memory, wherein the first data is assigned a first priority group state among the group states, the second data is assigned a second priority group state among the group states having a priority lower than that of the first priority group state, and the third data is assigned a third priority group state among the group states having a priority lower than that of the second priority group state;

in response to a received write data request including fourth data, determining whether sufficient free space exists in the first memory to store the fourth data;

in response to determining that sufficient free space exists in the first memory to store the fourth data, storing the fourth data in the first memory;

in response to determining that sufficient free space does not exist in the first memory to store the fourth data, re-allocating memory space in the first memory by overwriting the third data with at least a portion of the fourth data; and

changing, in response to completing a process executed upon previous write data written into the first memory, attribution information assigned to the previous write data to reflect that space storing the previous write data within the first memory is free space that is available to be overwritten without copying the previous write data from the first memory to the second memory.

13. The method of claim 12, further comprising:

completing a data processing operation in the memory system directed to the stored first data that changes attribution information associated with the stored first data by monitoring of the attribution information using an operating system running on the memory controller; and

changing the first group state assigned to the stored first data to a different group state.

14. The method of claim 12, further comprising:

upon determining that sufficient free space does not exist in the first memory for a residual portion of the fourth data other than the fourth data overwriting the third data, executing a flush operation that copies at least the stored second data from the first memory to the second memory; and

thereafter,

storing the residual portion of the fourth write data in the first memory.