US Patent 7830730 Semiconductor device

A memory module fast in random accesses, large in capacity, and low in fabricating cost. And the memory module can assure high security. The memory module consists of a flash memory, a dynamic random access memory, and a control circuit. The control circuit enables data transfer between the flash memory and the dynamic random access memory only with a read operation for a specific address in the memory module. When reading data from the memory module, the control circuit refreshes the dynamic random access memory. Thus the present invention can realize a large capacity and low cost memory module capable of reading data fast reading and assuring high security.