Integration scheme for retention-aware DRAM refresh

In DRAM refresh, due to a few cells that have lower retention time, it makes DRAM controller to raise refresh frequency to keep the data integrity, and produces unnecessary refresh for the other normal cells which resulting in large DRAM refresh overhead. To resolve this problem, we propose an integration scheme for DRAM refresh based on the retention-aware auto refresh (RAAR) method. With given distribution of weak cells in memory banks, our integration scheme can choose the most appropriate refresh technique in each refresh time. Experimental results show that the integration of refresh scheme can properly improve the system performance and have a great reduction on DRAM refresh power consumption.