Row hammer prevention circuit, a memory module including the row hammer prevention circuit, and a memory system including the memory module

摘要

A row hammer prevention circuit for providing a reference address to perform an additional refresh operation includes a history storage circuit configured to store one or more first addresses, each of the first addresses having been provided as the reference address. The row hammer prevention circuit further includes an address storage circuit configured to store a row address corresponding to an active command, a reference address storage circuit configured to store one or more second addresses, and a control circuit configured to provide the reference address in response to a refresh command.