JPS5798173A - Module selecting system of storage device - Google Patents

Abstract

PURPOSE:To easily extend the capacity of a memory without requiring a complicated setting operation, by providing each specific adding means, lower limit address comparing circuit and upper limit address comparing circuit on each memory array card. CONSTITUTION:Each memory array card 3-1-3-n is provided with an adding means 31 for adding the capacity portion of a memory array 10 placed in its own memory array card, to address information inputted from the memory array card of the following side, and outputting it to the memory array card of the preceding side, or a control part 2. Also, said memory array card is provided with a lower limit address comparing circuit 32 for comparing an inputted address information with an access address information sent out from an access request origin 1, and an upper limit address address comparing circuit 33 for comparing an output of the adding means 31 with the access address information. In this way, in accordance with outputs of the lower limit address comparing circuit 32 and the upper limit address comparing circuit 33, it is discriminated that the access address information is in an address area of the relevant memory array card 3, and a relevant memory array selecting signal is generated.