| 摘要 |
<p>A television (TV) includes a circuit board (PCB) into which a digital video interface (DVI) receiver integrated circuit (IC) may optionally be mounted, and also includes other video sources. The TV includes a processor or controller which controls its operation, and also includes an analog switch coupled to the analog sources and to the PCB at the receiver, for switching among video sources. A scan port of the IC is coupled by way of a resistor to a general purpose I/O (GPIO) port of the switch, for indicating the presence of DVI video. The resistor has a value which places a logic low at the GPIO port when the optional receiver is present, and to allow the GPIO port to be pulled high when it is absent. A controller determines the presence or absence of the optional DVI IC by examining the logic state of the GPIO port.</p> |
