An apparatus includes a first memory, a second memory, a processor configured to perform an initialization process including adding data that generates a first error to initialization data and storing the initialization data together with the added data in the first memory to initialize the first memory, and a controller configured to perform an exchanging process including, when a second error occurs in the second memory during reading or writing data from or to the second memory, copying the data stored in the second memory into the first memory and switching, using a selector, a memory for use in writing and reading data from the second memory to the first memory. The processor is configured to read data from the first memory and the second memory and detect a failure of the selector or a failure of the exchanging process depending on whether the first error occurs or not.