Memory device

An operating method of a memory device, wherein the memory device comprises a page buffer, and the page buffer comprises a plurality of buffer units corresponding to a plurality of memory cells, the operating method comprising:

• receiving a read command with respect to a first page of the memory device;
• storing first hard decision data based on a normal read level to a first latch of each buffer unit of the plurality of buffer units, wherein the first hard decision data is read from the first page through a first read operation corresponding to the read command;
• storing first soft decision data based on an offset level to a second latch of each buffer unit of the plurality of buffer units, wherein the first soft decision data is read from the first page;
• receiving, from a memory controller, a first command, the first command comprising a read request with respect to a second page of the memory device;
• outputting, to the memory controller, the first hard decision data after dumping the first hard decision data to a cache latch of each buffer unit of the plurality of buffer units, dumping the first hard decision data being performed in response to receiving the first command;
• receiving a second command from the memory controller while a second read operation with respect to the second page is being performed;
• in response to receiving the second command, dumping the first soft decision data to the cache latch during a dump-allowed section, the dump-allowed section being defined in the second read operation;
• and
• outputting, to the memory controller, the first soft decision data that is dumped to the cache latch.

A memory system comprising:

• a memory device comprising a page buffer, the page buffer configured to store data read from a page, wherein the page buffer comprises a plurality of buffer units corresponding to a plurality of memory cells, and each buffer unit of the plurality of buffer units comprises a first latch, a second latch, a third latch, and a cache latch;
• and
• a memory controller configured to:
• receive hard decision data based on a normal read level and receive soft decision data based on an offset level, wherein the hard decision data and the soft decision data are read from the page;
• control the memory device to sequentially perform a first read operation with respect to a first page and a second read operation with respect to a second page;
• in response to outputting a first command to the memory device, receive first hard decision data from the memory device after the second read operation has started, the first hard decision data read by the first read operation;
• and
• in response to outputting a second command to the memory device while the second read operation is being performed, receive first soft decision data from the memory device before the second read operation is completed, the first soft decision data read by the first read operation.