Patent ID: 8171185

Claim:
An electronic device communicating via a bus comprising: a first port connected to the bus; a second port connected to the bus; a first physical layer processing means connected to said first port performing physical layer processing for data input/output via said first port; a second physical layer processing means connected to said second port performing physical layer processing for data input/output via said second port, a first link layer processing means connected to said first physical layer processing means; a second link layer processing means connected to said second physical layer processing means; a storage device storing data pertaining to communication processing; a control means connected to said first and second physical layer processing means and said first and second link layer processing means, said control means selecting one of the following modes: a first mode wherein said first physical layer processing means and said second physical layer processing means are connected via a first communication path, and wherein said first port, said first physical layer processing means, said second physical layer processing means and said second port operate as communication nodes on the bus on a common protocol, or a second mode wherein said first physical layer processing means and said second physical layer processing means are not connected to each other, said first physical layer processing means and said first link layer processing means operate as a first communication node on the bus in a first protocol, and said second physical layer processing means and said second link layer processing means operate as a second communication node on the bus in a second protocol; said control means selecting said first mode or said second mode corresponding to an execution state of communication processing via the bus; a second communication path between said first link layer processing means and said second link layer processing means; wherein when said storage device is connected to said first port and another electronic device accessing said storage device is connected said second port, said control means selects said first mode when said communication processing is OFF and selects said second mode when said communication processing is ON; and wherein data input/output is performed via said second communication path.