Power-on detection of DVI receiver IC
View Patent ↗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.
1. A video display apparatus, comprising:
a signal processor having an input for processing one of video information and audio information;
a detector for generating at a terminal, during a first interval, a signal that is selectively indicative of a presence of said detector, when said detector is present, and of an absence of said detector, when said detector is absent, said detector, when present, being responsive to said input signal for generating at the same terminal, during a second interval that is different from said first interval, a signal that is selectively indicative of a presence at said input of an input signal, when said input signal is present, and of an absence of said input signal, when said input signal is absent, and
a controller responsive to said signals that are generated at said terminal for controlling a mode of operation of said signal processor.
2. The video display apparatus according to claim 1 , wherein both said detector and at least a portion of said signal processor are included in a common integrated circuit.
3. The video display apparatus according to claim 1 , wherein said input signal comprises a DVI signal.
4. The video display apparatus according to claim 1 , wherein said detector is responsive to a selection signal, during a start-up time interval, for generating said signal that is indicative of the presence and absence, respectively, of said detector.
5. The video display apparatus according to claim 1 , wherein said detector includes a semiconductor that actively drives said terminal, during said first interval, when said detector is present, and wherein a signal is generated at said terminal in a passive manner, when said detector is absent.
6. The video display apparatus according to claim 1 , wherein the signal that is indicative of the absence of said detector is generated by a pull-up resistor.
7. A system comprising:
a processor including a terminal for receiving at least a first signal, and operative in response to said first signal for determining the existence or nonexistence of a receiver circuit installed in the system, and responsive to reception of a second signal at said terminal for determining the existence or nonexistence of a particular signal applied to said receiver circuit installed.
8. The system according to claim 7 , wherein the system includes a video display apparatus.
9. The system according to claim 7 , wherein said input signal comprises a DVI signal.
10. The system according to claim 7 , wherein said receiver circuit comprises an integrated circuit for a DVI.