Patent ID: 9685218
Date: 2017-06-20
CPC Classifications: G11C

Claim:
1. A method of refreshing a dynamic random access memory (DRAM), the DRAM including a memory cell array, the memory cell array including a plurality of memory cell rows, each of the plurality of memory cell rows being refreshed in accordance with corresponding refresh address, the method comprising: counting a number of accesses to a first memory cell row of the plurality of memory cell rows during a predetermined time interval; measuring an accumulated access time of the first memory cell row during the predetermined time interval; and performing a first refresh operation on a second memory cell row and a third memory cell row based on the number of accesses to the first memory cell row and performing a second refresh operation on the second memory cell row and the third memory cell row based on the accumulated access time of the first memory cell row respectively, each of the second memory cell row and the third memory cell row being neighboring memory cell rows adjacent to the first memory cell row.