Non-volatile memory device, storage device, and operation method thereof

A method of operating a storage device including a storage controller and a non-volatile memory, the method comprising:

• transmitting a normal program command by the storage controller to the non-volatile memory via data lines;
• outputting a ready/busy signal by the non-volatile memory to the storage controller during a first program time in response to the normal program command;
• transmitting a second level program command by the storage controller to the non-volatile memory via the data lines;
• and
• outputting a ready/busy signal by the non-volatile memory to the storage controller during a second program time in response to the second level program command,
• wherein the second program time is longer than the first program time.

A non-volatile memory device comprising:

• a memory cell array comprising a plurality of memory cells;
• a row decoder connected to the memory cells via a word line and applying a program voltage and a verification voltage to the word line during a program operation;
• a page buffer circuit connected to the memory cell array via a bit line and applying a bit line voltage corresponding to data to be programmed to a selected bit line;
• an input/output (I/O) circuit receiving data or commands from outside via data lines and transmitting the data to the page buffer circuit;
• and
• a logic control circuit configured to
• output a ready/busy signal during a first program time in response to a normal program command received via the I/O circuit, and
• output a ready/busy signal during a second program time in response to a slow program command received via the I/O circuit, and
• wherein the second program time is longer than the first program time.