| 摘要 |
PURPOSE:To prevent lowering of the usage efficiency of a dynamic RAM, by searching a memory being in the address designation state to perform a refresh operation correspondingly to an address which is not designated. CONSTITUTION:When matrix array dynamic RAM11 is accessed through the CPU, the row line select signal through the decoder becomes high-level, and designation state storage FF15a corresponding to the row line in the address designation state is reset, and corresponding AND gates 17a... are closed. Consequently, RAMs of column lines corresponding to addresses which are not designated are refreshed according to search results of FF15a... dependent upon sense signals SR0... from refresh circuit 16. Consequently, interference in access dependent upon refresh is prevented to prevent lowering of the usage efficiency of the RAM. |
