US Patent 11354408 Technique for detecting and thwarting row-hammer attacks

A memory controller for a (DRAM) memory processes an (access) command for a target row in the memory, increments a count value for each victim row associated with the target row, and issues a (dummy activate) command for a victim row whose count value reaches a specified threshold. By tracking victim rows instead of target rows, the memory controller can thwart both single-sided and double-sided row-hammer attacks. The memory controller maintains the victim-row addresses and corresponding command counts in a TCAM memory to detect rows that may be prone to row-hammer attacks. If so, then the memory controller issues dummy activate commands to the corresponding memory rows to thwart such row-hammer attacks.