Self resetting high speed redundancy circuit and method thereof

摘要

A memory circuit includes a memory structure having sets of redundant columns where each set of redundant columns can replace a column of the memory array that may include a defective cell. Selection of the redundant columns for a memory access is accomplished by performing an address comparison between the address provided to the memory and one or more predetermined values that indicate which portion of the data array each set of redundant columns replaces. Based on this address comparison, a column redundancy select signal is asserted when a set of redundant columns is selected. For a read operation, the column redundancy select signal propagates through redundant column logic select the appropriate data from a particular set of redundant columns. This redundant data that is selected is substituted for data stored in the memory array for the read operation. A de-select feedback signal is generated based on the column redundancy select signal The de-select feedback signal is self resetting by causing the column redundancy select signal to be de-asserted after a time period adequate for the memory operation to complete.