Semiconductor memory device having easily redesigned memory capacity

摘要

Sub-blocks SBA 0 -SBA 3 , SBB 0 -SBB 3 , SBC 0 -SBC 3 , SBD 0 -SBD 3 respectively form four groups. In each group, a refresh end signal REF_END is successively transferred to the next sub-block. Therefore, when a refresh counter of the number of bits corresponding to the number of word lines present in a sub-block is provided in a central control circuit, a memory capacity can easily be redesigned by changing the number of sub-blocks and changing a group configuration of sub-blocks. As a result, there can be provided a memory core for embedded memory in which a memory capacity can easily be changed and a refresh control-related circuitry can easily be changed.