Patent ID: 8654628

Claim:
A data control device comprising: a switch device that has a plurality of first terminals on an upstream side, a plurality of second terminals on a downstream side, and an internal circuit that optionally switches a connection between the first terminals and the second terminals based on an external switching signal; and at least one controller that has a first input/output port on the upstream side and at least one second input/output port on the downstream side, wherein the at least one second input/output port is directly connected to one of the first terminals of the switch device and the first input/output port is directly connected to one of the second terminals of the switch device, and wherein the at least one controller controls an input/output of data between the first input/output port and the second input/output port; wherein at least one of the first terminals of the switch device is connected to an upper device and the first input/output port of the at least one controller is connected to the upper device via the connection of the said one of the second terminals of the switch device with the first input/output port; wherein the upper device transmits a request to read or write data from or to a first memory device, respectively; wherein the first memory device is connected to one of the second terminals; wherein the internal circuit of the switch device performs switching in response to detecting a fault in the first memory device on the basis of the external switching signal; wherein the switching connects a second memory device to the one of the second terminals and disconnects the first memory device from the one of the second terminals; and wherein when a fault is detected in the at least one controller on the basis of the external switching signal, the internal circuit of the switch device performs switching to disconnect the at least one controller from at least the first or second memory device and a controller other than the at least one controller.