To eliminate the useless updating of data by preparing a control means applying the longest time no-use system and a control means which performs the estimation control of continuous addresses via the direct.memory.access(DMA) as the replacement means of the data stored in a cache memory.

A control means applying the longest time no-use system and a continuous address estimation control part 10 using the DMA are prepared as the replacement means of the data stored in a cache memory. The part 10 updates first the data corresponding to the address tags closer to the continuous addresses obtained via the DMA. Then the part 10 outputs data to a replacement control part 6, an R/W tag control part 9 and a data control part 7 based on the control signals received from a DMA control detection part 11, etc. A data RAM 2 undergoes the replacement control via the signals received from both parts 6 and 7.