Patent ID: 7668837

Claim:
A multiplex apparatus comprising: a plurality of systems configured to be connected to each other by links, wherein each of said plurality of systems comprises: a CPU, a pseudo legacy device configured to be electrically connected to said CPU, and a legacy device configured to be electrically connected to said pseudo legacy device, said pseudo legacy device comprises: a request buffer configured to store a request when said CPU sends said request through said pseudo legacy device to said legacy device, a pseudo operator configured to execute an emulation with regard to said legacy device based on said request, and store said emulation result including an inside status of said legacy device, and a response buffer configured to store a response to said request from said legacy device, said response buffer is unidirectional and separate from said request buffer, wherein said pseudo legacy device further comprises: a comparison error detector configured to compare said response outputted from said response buffer with an expectation value outputted from said pseudo operator, wherein said expectation value is obtained by said emulation, and an operation unit configured to output said expectation value as said response to said CPU, when discrepancy occurs between said response and said expectation value, based on said comparison result.