STORAGE SYSTEM, INFORMATION PROCESSING SYSTEM AND METHOD FOR CONTROLLING NONVOLATILE MEMORY

• US 20170262175A1
• Filed: 08/29/2016
• Published: 09/14/2017
• Est. Priority Date: 03/08/2016
• Status: Active Grant

• Current Assignee: Kioxia Corporation
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: KANNO, Shinichi
• Granted Patent: US 10,353,612 B2
• Time in Patent Office: Days
• CPC Class Codes: G06F 3/061 Improving I/O performance
• CPC Class Codes: G06F 3/0619 in relation to data integrity, e.g. data losses, bit errors
• CPC Class Codes: G06F 3/064 Management of blocks
• CPC Class Codes: G06F 3/0652 Erasing, e.g. deleting, data cleaning, moving of data to a wastebasket
• CPC Class Codes: G06F 3/0659 Command handling arrangements, e.g. command buffers, queues, command scheduling
• 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

Abstract

According to one embodiment, a storage system includes a nonvolatile memory and a controller. The controller classifies blocks in the nonvolatile memory into a plurality of first blocks and a plurality of second blocks organized as a plurality of block groups each including a set of blocks. The controller receive a first read, write or erase command from a host, and performs a read, write or erase operation on one first block in the first blocks that is designated by a physical address of the first read, write or erase command. The controller receive a second read, write or erase command from the host, and performs a read, write or erase operation on blocks in one block group in the block groups that is designated by a physical address of the second read, write or erase command.

Claims

1. A storage system comprising:

a nonvolatile memory including a plurality of blocks; and

a controller electrically connected to the nonvolatile memory,

wherein the controller is configured to;

classify the blocks into a plurality of first blocks and a plurality of second blocks, the second blocks being organized as a plurality of block groups each including a set of blocks;

receive a first read, write or erase command from a host, the first read, write or erase command including a physical address designating one first block in the first blocks;

perform a read, write or erase operation on the one first block that is designated by the physical address of the first read, write or erase command;

receive a second read, write or erase command from the host, the second read, write or erase command including a physical address designating one block group in the block groups; and

perform a read, write or erase operation on blocks included in the one block group that is designated by the physical address of the second read, write or erase command.

2. The storage system of claim 1, wherein

when the host requests allocation of one block, the controller allocates one first block in the first blocks for the host, and notifies the host of a physical address designating the allocated one first block;

and

when the host requests allocation of one block group, the controller allocates one block group in the block groups for the host, and notifies the host of a physical address designating the allocated one block group.

3. The storage system of claim 1, wherein each of the block groups includes a plurality of blocks that can be accessed in parallel.

4. The storage system of claim 3, wherein a combination of physical addresses of blocks belonging to each of the block groups is determined from a physical address designating said each of the block groups, based on a mathematical rule.

5. The storage system of claim 4, wherein when a combination of physical addresses of a plurality of blocks determined from a physical address designating a first block group of the block groups, based on the mathematical rule includes a physical address designating a bad block, the controller selects another block which is accessible in parallel with all blocks of the first block group excluding the bad block, and replaces the bad block with the selected block.

6. The storage system of claim 1, wherein

the controller is configured to:

when the first read, write or erase command is a first erase command including a physical address designating one first block in the first blocks, erase the one first block in the first blocks that is designated by the physical address included in the first erase command;

manage erase counts of the respective first blocks;

when the second read, write or erase command is a second erase command including a physical address designating one block group in the block groups, erase blocks of the one block group in the block groups that is designated by the physical address included in the second erase command;

manage erase counts of the respective block groups;

notify the host of an erase count of one first block in the first blocks when the host requests acquisition of the erase count of the one first block; and

notify the host of an erase count of one block group in the block groups when the host requests acquisition of the erase count of the one block group.

7. The storage system of claim 1, wherein

the controller is configured to:

manage blocks included in the first blocks and holding valid data, and blocks included in the first blocks and holding no valid data;

manage block groups included in the block groups and holding valid data, and block groups included in the block groups and holding no valid data;

allocate, for the host, one block included in the blocks holding no valid data, erase the allocated block, and notify the host of a physical address designating the allocated and erased block, when the host requests both allocation of one block and erasure of the one block; and

allocate, for the host, one block group included in the block groups holding no valid data, erase the allocated block group, and notify the host of a physical address designating the allocated and erased block group, when the host requests both allocation of one block group and erasure of the one block group.

8. The storage system of claim 7, wherein

the controller is configured to:

manage erase counts of the respective first blocks, and erase counts of the respective block groups;

select, from the blocks holding no valid data, a block having a minimum erase count as one block to be allocated for the host, when the host requests both allocation of one block and erasure of the one block; and

select, from the block groups holding no valid data, a block group having a minimum erase count as one block group to be allocated for the host, when the host requests both allocation of one block group and erasure of the one block group.

9. An information processing system comprising a storage system and a host,

wherein

the storage system comprises:

a nonvolatile memory including a plurality of blocks; and

a controller electrically connected to the nonvolatile memory, and configured to classify the blocks into a plurality of first blocks and a plurality of second blocks, the second blocks being organized as a plurality of block groups each including a set of blocks,

the host comprises;

a memory; and

a processor configured to execute a program stored in the memory,

wherein the processor is configured to;

transmit, to the storage system, a first read, write or erase command including a physical address designating one first block in the first blocks; and

transmit, to the storage system, a second read, write or erase command including a physical address designating one first block group in the block groups, and

wherein the controller is configured to;

perform a read, write or erase operation on the one first block that is designated by the physical address of the first read, write or erase command; and

perform a read, write or erase operation on blocks included in the one block group that is designated by the physical address of the second read, write or erase command.

10. A control method of controlling a nonvolatile memory including a plurality of blocks, comprising:

classifying the blocks into a plurality of first blocks and a plurality of second blocks, the second blocks being organized as a plurality of block groups each including a set of blocks;

receiving a first read, write or erase command from a host, the first read, write or erase command including a physical address designating one first block in the first blocks;

performing a read, write or erase operation on the one first block that is designated by the physical address of the first read, write or erase command;

receiving a second read, write or erase command from the host, the second read, write or erase command including a physical address designating one block group in the block groups; and

performing a read, write or erase operation on blocks included in the one block group that is designated by the physical address of the second read, write or erase command.

11. The control method of claim 10, further comprising:

allocating one first block in the first blocks for the host, and notifying the host of a physical address designating the allocated one first block, when the host requests allocation of one block; and

allocating one block group in the block groups for the host, and notifying the host of a physical address designating the allocated one block group, when the host requests allocation of one block group.

12. The control method of claim 10, further comprising:

managing blocks included in the first blocks and holding valid data, and blocks included in the first blocks and holding no valid data;

managing block groups included in the block groups and holding valid data, and block groups included in the block groups and holding no valid data;

allocating, for the host, one block included in the blocks holding no valid data, erasing the allocated block, and notifying the host of a physical address designating the allocated and erased block, when the host requests both allocation of one block and erasure of the one block; and

allocating, for the host, one block group included in the block groups holding no valid data, erasing the allocated block group, and notifying the host of a physical address designating the allocated and erased block group, when the host requests both allocation of one block group and erasure of the one block group.

13. The control method of claim 12, further comprising:

managing erase counts of the respective first blocks, and erase counts of the respective block groups;

selecting, from the blocks holding no valid data, a block having a minimum erase count as one block to be allocated for the host, when the host requests both allocation of one block and erasure of the one block; and

selecting, from the block groups holding no valid data, a block group having a minimum erase count as one block group to be allocated for the host, when the host requests both allocation of one block group and erasure of the one block group.