Patent ID: 7137029

Claim:
An information processor, comprising: a CPU; an input/output device that is provided with an input device for applying data or commands as input to said CPU and an output device for supplying as output commands or the results of data processing that are issued from said CPU; two chip sets that are each provided with a serial controller, said chip sets operating as a working system that normally operates or a reserve standby system, said chip sets being an I/O interface that is interposed between said CPU and said input/output device; a selector for switching the connection routes of said serial controllers and said input/output device when a fault occurs in one of said two chip sets; and a service processor for controlling said selector to cause the output data of said serial controller of said working system to be supplied to said output device and data from said input device to be supplied to each of said two serial controllers when no fault has occurred in said chip sets, and upon receiving notification of the occurrence of a fault from either one of said chip sets, to cause only output data of the serial controller that is provided in the chip set that is operating normally to be supplied as output to said output device and to cause data from said input device to be supplied only to the serial controller that is provided in the chip set that is operating normally.