Target row refresh mechanism capable of effectively determining target row address to effectively mitigate row hammer errors without using counter circuit

Abstract

A target row refresh method includes: providing first table having M entries each capable of storing information of target row address; providing second table having K entries respectively capable of storing information of different/identical candidate row addresses; determining whether an input address in an input address register matches address information recorded in the first table; when not match, determining whether to update information of a target row latch by using the input address in the input address register according to a sample policy so as to determine whether to compare the input address with address information recorded in the second table to determine a target row address; and performing a target row refresh operation to refresh a memory device's row(s) adjacent to a target row corresponding to the target row address.