Memory device for supporting cache read operation, operating method thereof, and memory system including the same

A memory system comprising:

• a memory device including a memory cell array including a plurality of memory cells coupled between a plurality of word lines and a plurality of bit lines and a plurality of page buffers coupled to the plurality of bit lines, each page buffer including a first latch and a second latch;
• and
• a controller configured to generate a first cache read command for cache-reading data of a page coupled to a first word line among the plurality of word lines, to transfer the first cache read command to the memory device, to generate a second or third cache read command, and to transfer the second or third cache read command to the memory device,
• wherein, when the second or third cache read command is inputted in a section in which a first storage operation of reading data of the page coupled to the first word line in response to the first cache read command and storing the read data in the first latch or a discharge operation of discharging the first word line after the first storage operation is performed, the memory device performs the discharge operation and a moving operation of moving the data of the first latch to the second latch in an at least a partially overlapping manner.

An operating method of a memory device including a memory cell array including a plurality of memory cells coupled between a plurality of word lines and a plurality of bit lines and a plurality of page buffers coupled to the plurality of bit lines, each page buffer including a first latch and a second latch, the operating method comprising:

• a first storage operation of storing data of a page coupled to a first word line among the plurality of word lines in the first latch in response to input of a first cache read command;
• a discharge operation of discharging the first word line after the first storage operation;
• a moving operation of moving the data of the first latch to the second latch after the first storage operation;
• and
• a parallel execution operation of performing an execution section of the discharge operation and an execution section of the moving operation in such a way that the execution sections partially overlap each other when a second or third cache read command is inputted in a section in which the first storage operation or the discharge operation is performed.