Power connection between serial interfaces

An apparatus, comprising:

• a first and a second serial interface, each comprising at least one data line and at least one power supply line;
• a switching unit configured to connect or disconnect a power terminal of the first serial interface to a power terminal of the second serial interface based on a voltage level at an identification terminal of the second serial interface.

A method, comprising

• identifying a voltage level at an identification terminal of a second serial interface;
• and
• connecting or disconnecting a power terminal of a first serial interface to a power terminal of the second serial interface based on the identified voltage level, wherein each interface comprises at least one data line and at least one power supply line.

A computer program product comprising a computer-readable medium bearing computer program code embodied therein for use with a computer, the computer program code comprising:

• code for identifying a voltage level at an identification terminal of a second serial interface;
• and
• code for connecting or disconnecting a power terminal of a first serial interface to a power terminal of the second serial interface based on the identified voltage level, wherein each interface comprises at least one data line and at least one power supply line.