Replaceable device and method for cache memorizer

The invention relates to a replaceable device and method for a cache memorizer. The replaceable device comprises a PLRU (pseudo least recently used) memorizer, an LRU (least recently used) memorizer, an LRU arithmetic element and a cache line selection module. The LRU arithmetic element performs least recently used operation on multiple memorizer blocks to output a selection control signal according to multiple block mark bits in the LRU memorizer. The cache line selection module performs virtual least recently used operation on the multiple cache lines to select a target cache line accordingto the selection control signals and the multiple cache mark bits in the PLRU memorizer. With the advantages of the least recently used calculating method and the virtual least recently used calculating method, the device and the method in the invention can reduce the circuit area of the replaceable device of the cache memorizer and improve the time sequence of the device.