| 摘要 |
PURPOSE:To form a semiconductor memory with redundant constitution which will not cause delay of access time at the time of selecting a standby word line by enlarging cell capacity of memory connected to a standby word line. CONSTITUTION:When a word line 14 in an address (i) has troubles and is replaced with a standby word line 16, the address (i) is written in a standby row decoder 2. Here, it is assumed that bit line capacity, cell capacity of a memory cell 6 connected to the word line 14 of the main body, and that of a memory cell 10 connected to the standby word line 16 are CD, CS and CSR, respectively, and an electric potential either at a power source level VDD or at a grounding level ''0'' is stored and held at the CS and the CSR. A bit line 12 is precharged at an intermediate potential VDD/2 of two levels stored and held in the memory cells 6 and 10 at the time of reading. Even if information stored in the CS and CSR is different, the larger potential change than that at the time of selecting only the word line of the main body can be obtained by enlarging the CSR. |
