DRAM Refresh Controller Selective Masking

The memory block is segmented into multiple word lines, and the refresh operation is further segmented at the row level. The refresh controller independently controls each row within a word line, allowing selective refreshing of only those rows that contain valid data, thereby avoiding unnecessary refresh operations on entire memory blocks and reducing power consumption while maintaining data reliability.

The refresh operation transitions from a uniform approach (refreshing entire memory blocks) to a localized approach (refreshing only specific rows within word lines). The refresh controller identifies and refreshes only the local regions (rows) that contain valid data, applying different refresh behavior to different parts of the memory based on their actual data status, thus optimizing power consumption while ensuring data retention.

The memory system performs self-diagnosis to identify which rows contain valid data. The refresh controller automatically detects the data status of each row and independently decides whether to perform refresh operations, eliminating the need for external control or complex centralized management. This self-service mechanism reduces power consumption through selective refresh while keeping the control logic relatively simple and distributed.

The system performs preliminary detection of data presence in each row before executing refresh operations. The refresh controller预先 identifies which rows contain valid data and prepares the refresh operation accordingly, avoiding unnecessary refresh actions on empty rows. This preliminary action enables power-efficient selective refresh without requiring complex real-time decision-making during the refresh process.