| 摘要 |
In the case that a refresh operation is carried out which is independent from an external access operation, a data access method of a semiconductor memory device and a semiconductor memory device are provided by which time suitable of each of these external access operation and refresh operation is set. While a time-measuring start signal (SIN) is entered into a path switching means (2), the path switching means (2) is connected to either a first timer section (4) or a second timer section (3) under control of an external-access-operation-start-request signal (REQ(O)) and a refresh-operation-start-request signal (REQ(I)). Both the first and second timer sections (4,3) measure both time " tau O" and time " tau I" to output a time-measuring stop signal "SOUT". The measuring time " tau O" corresponds to differential amplification time of a bit line pair when the external access operation is carried out, whereas the measuring time " tau I" corresponds to differential amplification time when the refresh operation is carried out. Alternatively, the measuring time " tau O" may be varied by reading/writing operations so as to be set. As a consequence, proper amplification time can be set every operation mode. <IMAGE> |
