Memory system and method of operating the same

A method of operating a memory system, the memory system including a non-volatile memory, the non-volatile memory including a memory cell region including a memory block and a first metal pad, and a peripheral circuit region including a second metal pad and vertically connected to the memory cell region by the first metal pad and the second metal pad, the method comprising:

• measuring, using processing circuitry, an erase program interval (EPI) of the memory block in response to a write request received from a host, the EPI being a time period from an erase time point to a program time point of the memory block;
• and
• performing, using the processing circuitry, a program operation on the memory block in a first program mode or a second program mode based on a duration of the EPI, the first program mode including writing N-bit data to each memory cell of the memory block, and the second program mode including writing M-bit data to each memory cell of the memory block, the performing the program operation on the memory block including adjusting at least one voltage level of the program operation based on the first program mode or the second program mode,
• wherein N and M are positive integers, and M is less than N.

A memory system comprising:

• a non-volatile memory comprising:
• a memory cell region including a plurality of memory groups and a first metal pad, and
• a peripheral circuit region including a second metal pad and vertically connected to the memory cell region by the first metal pad and the second metal pad;
• and
• a memory controller configured to,
• measure an erase program interval (EPI) of a first memory group from among the plurality of memory groups, the EPI being a time period from an erase time point to a program time point of the memory group,
• determine a plurality of program modes based on a number of data bits stored in each memory cell of the memory group,
• select a program mode for the first memory group from the plurality of program modes based on the measured EPI, and
• control a program operation on the first memory group based on the selected program mode of the first memory group, the controlling the program operation including adjusting at least one voltage level associated with the program operation based on the selected program mode.