Data storage apparatus and operating method thereof

An operating method of a data storage apparatus which includes a nonvolatile memory device including a plurality of memory blocks in which a plurality of word lines to which one or more pages are coupled are arranged and a controller configured to control the nonvolatile memory device, the method comprising:

• performing a write operation on a first word line and then on a second word line adjacent to the first word line;
• detecting occurrence of sudden power-off (SPO) of the data storage apparatus after or during the write operation on the second word line;
• detecting one or more first pages coupled to the first word line, in which an interference has occurred due to the write operation on the second word line;
• and
• selectively storing data corresponding to data stored in the one or more first pages, among data buffered in a data buffer, in a backup memory block of a nonvolatile memory device.

A memory system comprising:

• a memory block including page planes arranged in a first direction, each coupled to a word line and each having pages arranged in a second direction, each page having quadruple level cells (QLCs) arranged in a third direction;
• and
• a controller configured to selectively back up, when a sudden power off (SPO) occurs during a program operation to the memory block, buffered data to be programmed into one or more pages between interrupted and interfered pages of the memory block,
• wherein the interrupted page is a page to which the program operation is interrupted due to the SPO, and
• wherein the interfered page is a page within a page plane, which is arranged adjacent to a page plane of the interrupted page, in which a program operation was completed before the interrupted program operation and stored data was damaged due to the program operation being performed on the page plane of the interrupted page.