Methods and devices for identifying devices coupled to a data processing apparatus

摘要

A scanner unit changes a first wire included in a pair of wires in Low condition into High condition, sets another second wire in Low condition during the change, and identifies whether a CISM coupled with a resistor is or a CISM coupled with no resistor is by inputting a signal from the second wire afterward. Further, the controller changes the first wire in High condition into Low condition, sets the second wire in High condition during the change, and identifies the CISM by inputting a signal from the second wire. The scanner unit sets the second wire in condition before being changed while changing condition of the first wire so as to prevent an effect of a signal (crosstalk) caused when the condition of the first wire is changed more effectively.

主权项

1. A data processing apparatus comprising:
a controller; and at least a pair of wires having a first end that is coupled with the controller and a second end that is coupled with one of a first coupled device having at least a pair of signal lines and a resistor that is coupled with the pair of signal lines and a second coupled device having at least a pair of signal lines but no resistor that is coupled with the pair of signal lines, and wherein the controller is configured to change a first wire of the pair of wires in a first condition into a second condition, to set a second wire ene of the pair of wires into the first condition during the change, and to identify the first or the second coupled device by inputting a first signal from the second wire after the change.