Memory system and memory module including memory chips sharing channel

A memory module, comprising:

• a command/address bus;
• a plurality of data buses;
• and
• a plurality of memory chips each including a plurality of banks and each suitable for generating a tracking address by tracking a row-hammer risk of selected banks among the banks, encrypting the tracking address using an encryption key to output tracking information to a corresponding data bus of the data buses and performing a target refresh operation according to a row-hammer address transferred through the command/address bus.

An operation method of a memory system, comprising:

• generating, at each of memory chips, a tracking address by tracking a row-hammer risk of selected banks among a plurality of banks included in each of the memory chips;
• encrypting, at each of the memory chips, the tracking address using an encryption key to output tracking information to a corresponding data bus of a plurality of data buses;
• collecting, at a memory controller, the tracking information for the banks transferred through the plurality of data buses to generate and output a row-hammer address to a command/address bus;
• and
• performing, at each of the memory chips, a target refresh operation according to the row-hammer address transferred through the command/address bus.