US Patent 10185609 Virtual timer for data retention

Approaches, techniques, and mechanisms are disclosed for improving data retention using a virtual timer. A memory controller may use a raw bit error rate (RBER) to find an equivalent temperature-accelerated data age of a data item. The data age is computed by using the initial RBER of virtual timing data (VTD) as a virtual write in time of the data item compared to a present time using the current RBER of the VTD. When the data age is determined to exceed a data retention threshold, a data refresh is performed on the data item at the memory block on the memory device. The data age may be stored as virtual timing data on the memory block.