| 摘要 |
Apparatus is provided for substituting a spare column of memory cells in a byte wide memory for a defective column of cells in such memory. The apparatus includes a spare column of memory cells, an electrically conductive line 13, a spare decoder 16 for switchably connecting the line 13 to the spare column, a first fuse FSD1 between the spare column and the line 13, a series of second fuses FS controlling a series of switches T1, T2 . . . between the line 13 and corresponding sense amplifiers 11, and a series of third fuses FD, each connected between a corresponding column and the sense amplifier associated with that column. The spare column of memory cells is connected to the appropriate sense amplifier by blowing the appropriate fuse FS and supplying the necessary address information to spare decoder 16. The defective column of memory cells may be disconnected by blowing the appropriate fuse FD. |
