| 摘要 |
PURPOSE:To prevent the increase in the access time, by making an arrangement that, when a faulty memory cell is selected, the faulty memory cell and a standby memory cell on a bit line to be connected to the same sense amplifier which is connected with the faulty memory cell are simultaneously read out. CONSTITUTION:A memory of a redundancy constitution is composed of two mats A and B and two bit lines B are connected to the same sense amplifier 4. An acting memory cell 1, standby memory cell 2', and dummy memory cell 3 are connected to each bit line, and the standby memory cell 2' has a larger cell capacity than the acting memory cell 1 has. A standby low decoder 7' holds the address of a faulty memory cell on the other bit line B. When a faulty memory cell of the mat A is selected, the dummy decoder 8' and the standby low decoder 7' simultaneously activate the dummy cell 3 of the mat A and the standby memory cell 2' of the mat B, respectively. Therefore, the increase in the access time is suppressed. |
