Compact column redundancy cam architecture for concurrent read and write operations in multi-segment memory arrays

Abstract

A memory system incorporating redundancy utilizes a content addressable memory to monitor addresses during memory accesses. The content addressable memory provides a pointer to an alternate memory location when a previously determined faulty location is requested. Redundant memory cells are accessed by use of column redundancy information output from the content addressable memory. During a memory access cycle a register in the content addressable memory latches a memory address. The content addressable memory decodes the address and produces column redundancy information as an output. The column redundancy information is latched during a period complementary to the memory access cycle. By utilizing complementary memory access phases to latch memory addresses in contrast with a utilization of column redundancy information, a single set of registers may be used. Additionally, concurrent read and write operations are supported.