User device including storage device and trim management method thereof

A storage device comprising:

• a nonvolatile memory;
• a buffer memory configured to temporarily store data;
• and
• a storage controller configured to,
• transmit a trim request to an external device,
• receive a pattern check start command from the external device,
• receive a trim pattern from the external device,
• transmit a stop request to the external device,
• receive a pattern check stop command from the external device,
• perform at least one pattern check operation in response to the pattern check start command until the storage controller receives the pattern check stop command, and
• write the data or perform at least one trim operation in the nonvolatile memory based on results of the at least one pattern check operation.

A method comprising:

• transmitting, by a storage controller in a storage device, a trim request to an external device based on a number of free blocks of the storage device or available memory capacity of the storage device;
• receiving, by the storage controller, a pattern check start command from the external device;
• receiving, by the storage controller, a trim pattern from the external device;
• performing, by the storage controller, a pattern check operation in response to the pattern check start command;
• receiving, by the storage controller, a pattern check stop command from the external device;
• stopping, by the storage controller, the pattern check operation in response the pattern check stop command;
• and
• writing data or performing a trim operation, by the storage controller, in a nonvolatile memory in the storage device based on results of the pattern check operation.