Apparatus for controlling access to a memory device and memory system comprising the same

A memory system, comprising:

• at least one memory module comprising rows of memory units;
• and
• an apparatus for controlling access to the at least one memory module;
• wherein the apparatus comprises:
• an operation monitor configured to track memory operations to the rows of memory units of the at least one memory module;
• a row hammer counter configured to determining, for each of the rows of memory units, row hammer effects experienced by the row of memory units due to the memory operations to the other rows of memory units of the at least one memory module;
• a mitigation module configured to initiate, for each of the rows of memory units, row hammer mitigation in case that accumulated row hammer effects experienced by the row of memory units reach a predetermined threshold;
• and
• a virtual host module configured to perform the row hammer mitigation targeting a row of memory units in response to the initiation of row hammer mitigation for the row of memory units by the mitigation module.