Semiconductor storage device

摘要

Four memory banks (10 to 13), each having a hierarchical word line structure, are provided. If a particular mode for one of the memory banks is specified by a control packet (PKT), a mode recognizer (15) produces the leading edges of change-of-sub-word enable (SEN0-3) and change-of-column enable (CEN0-3) signals with the logical level of change-of-main-word enable (MEN0-3) signal fixed. This is done to make activated ones of sub-word and column select lines changeable in each of the memory banks with the same main word line still selected. In this manner, the row access speeds increase for the respective memory banks.