Halbleiterspeicher mit Multiplex-Redundanz

摘要

An integrated circuit memory is disclosed which includes redundant columns associated with a sub-array, and in which multiple input/output terminals are placed in communication with multiple columns in the sub-array in read and write cycles. The number of redundant columns per sub-array is less than the number of input/output terminals. A multiplexer connects the selected redundant column to a selected sense amplifier and write circuit for the input/output with which the replaced column was associated. The multiplexer includes pass gates connected to the bit lines of the redundant column, and fuses connected between each of the pass gates and each of the sense/write circuits selectable for the redundant column. Those of the fuses which are not associated with the selected input/output are opened, and the fuses associated with the selected input/output are left intact. Precharge transistors are connected to the fuse sides of the pass gates, for precharging each of the floating nodes after the pass gates are turned off. This precharging negates the effect of any charge which may be trapped on the fuse side of the pass gates for those lines where the fuses are opened, so that the access time for the next cycle will not be degraded.