Memory system, memory controller, and method for operating memory system for determining read biases for read retry operation

A memory controller comprising:

• a memory interface configured to communicate with a memory device comprising a plurality of memory areas;
• and
• a control circuit configured to control, when performing a read retry operation on a target memory area of the plurality of memory areas, the memory device to:
• perform a first read retry operation on the target memory area at least one read bias of multiple read biases in a priority read bias group, among a plurality of read biases in a read retry table;
• and
• perform, according to a result of the first read retry operation, a second read retry operation on the target memory area using one or more remaining read biases, not in the priority read bias group, in the read retry table,
• wherein the read biases in the priority read bias group are selected prior to the remaining read biases when performing the read retry operation on the target memory area, and
• wherein, when performing the first read retry operation, a first read bias in a priority read bias group, used for the first read retry operation, is selected on the basis of the number of times reading data from any one of a plurality of memory areas succeeded during a set time period.

A method for operating a memory system, the method comprising:

• performing a first read retry operation on a target memory area at least one read bias of multiple read biases in a priority read bias group, among a plurality of read biases in a read retry table;
• and
• performing, according to a result of the first read retry operation, a second read retry operation on the target memory area using one or more remaining read biases, not in the priority read bias group, in the read retry table,
• wherein the read biases in the priority read bias group are selected prior to the remaining read biases when performing the read retry operation on the target memory area, and
• wherein, when performing the first read retry operation, the first read bias in a priority read bias group, used for the first read retry operation, is selected on the basis of the number of times reading data from any one of a plurality of memory areas succeeded during a set time period.