Storage control apparatus

In a storage control apparatus provided therein with a battery-backed-up memory device being a combination of a cache memory of a storage device and a system memory on the side of a CPU, an ASIC (Application-Specific Integrated Circuit) having a virtual window function is provided to a system, and I/O from a front end and/or a back end is performed via a virtual window, thereby making an addition of data integrity code, and performing automatic dual write of data. With such a storage control apparatus provided therein with a battery-backed-up memory being a combination of a CS/DS (Code Storage/Data Storage) and a cache, implemented are protection of block data, and dual write into a Cache (user data, control data) so that the reliability can be kept at the time of data input/output control.