Abstract: A memory card has a plurality of non-volatile memories and a main controller for controlling the operation of the non-volatile memories. The main controller performs an access control to the non-volatile memories in response to an external access instruction, and an alternate control for alternating an access error-related storage area of the non-volatile memory with other storage area. In the access control, the speeding up of the data transfer between flash memories is achieved by causing the plurality of non-volatile memories to parallel access operate. In the alternation control, the storage areas is made alternative for each non-volatile memory in which an access error occurs.

Abstract: This invention realizes separate control for each memory area. A memory unit is structured by including a semiconductor memory device capable of memorizing information, the aforementioned memory device is divided into plural memory areas logically and also management table, which is capable of controlling separately each aforementioned memory area for accessing from the outside, is tabled, control information, which prohibits accessing the prescribed memory area of the aforementioned plural memory areas, is provided in the aforementioned management information, and it is prohibited to access the specified memory area from the outside in accordance with control information.

Abstract: The present invention provides a nonvolatile memory system whose storage capacity can be easily changed. The nonvolatile memory system comprises plural memory modules, a controller for controlling the operation of the plural memory modules according to access requests from the outside, and a module selecting decoder for selectively enabling the memory modules by decoding a selection signal outputted from the controller, wherein the memory modules are freely mounted or dismounted. With this arrangement, the storage capacity can be changed by increasing or decreasing the memory modules.