Memory device and method for protecting a memory device from the effect of row hammering

Abstract

The invention relates to a method for protecting a memory device () from the effect of row hammering. The memory device () comprises a DRAM unit (U) formed by a plurality of memory point matrices (MAT-MATN) subdivided into a plurality of memory blocks (B-BM). The memory device () comprises activation counters (CTR-CTRM) respectively associated with the memory blocks (B-BM). The method comprises the execution, with each activation of a row of a given block (Bi), of a step of incrementing the activation counter (CTRi) associated with the given block (Bi); and the initiation of the preventive refresh of all the rows of the given block (Bi) when the activation counter (CTRi) of this given block (Bi) exceeds a threshold value (Si). The protection method also comprises at least one of the operations aimed at: —including, in the preventive refresh, at least some of the rows of at least one block directly adjacent (Bi+1, Bi−1) to the given block (Bi); —incrementing, during the activation of the row or of certain rows of the given block (Bi), the activation counter (CTRi−1, CTRi+1) of at least one block directly adjacent (Bi−1, Bi+1) to the given block (Bi) and initiating the preventive refresh of all the rows of the adjacent block (Bi−1, Bi+1) when the activation counter (CTRi−1, CTRi+1) associated with this adjacent block (Bi−1, Bi+1) exceeds a threshold value (Si−1, Si+1).