Patent ID: 7150032

Claim:
A method for using a plurality of transmission lines of a digital bus having a plurality of transmission lines operable in a first connection mode and a second connection mode, comprising the steps of: forming a first transmission line using said first connection mode with the first transmission line being adapted to transmit data sent out from one of plural electronic apparatuses coupled to the digital bus so as to be receivable by all other electronic apparatus, forming a second transmission line using said second connection mode with the second transmission line being adapted to transmit data between only two predetermined electronic apparatus and said second line not communicating data transmitted from electronic apparatus other than said predetermined electronic apparatus, pre-selecting the plurality of transmission lines of the digital bus into groups before any transmission lines among the plurality of transmission lines is formed, said groups including a first group that transmits data only in said first connection mode, and a second group that transmits data only in said second connection mode, classifying said plurality of electronic apparatus connected to said digital bus into groups including a first group that receives data substantially through a transmission line of said first connection mode and a second group that receives data substantially through a transmission line of said second connection mode, wherein the plurality of electronic apparatus connected to said digital bus are classified into the first and second groups by inquiring whether each electronic apparatus connected to said digital bus includes a monitor apparatus to display a supplied signal; and assigning some of said plurality of transmission lines to said first connection mode based on the status of whether a default channel for an electronic apparatus having said monitor apparatus is used or occupied by another apparatus and the remaining transmission lines to the second connection mode.