Figure 39: DVI-I reference schematic
2.8.2.2 HDMI Schematic Example
The HDMI connector does not feature an Analogue VGA interface, but there is an optional
Consumer Electronics Control (CEC) interface available. This single-wire interface is used to control
consumer audio and video devices such as televisions or AV receivers. There are many different
trade names for CEC (VIERA Link, Anynet+, EasyLink, Aquos Link, BRAVIA Link, etc.) The CEC is a
3.3V interface. Nevertheless, it is recommended that a level shifter is added. This eliminates
problems with displays that may pull-up the signals to other voltage levels.
The I
2
C signals for the DDC and the hot-plug detection (HPD) need to be shifted to/from the 5V
logic level of the HDMI interface to the Apalis module signal level of 3.3V. The DDC requires
external pull-up resistors on the carrier board. The HPD has a pull-down resistor already on the
module. Since the HPD and CEC signals are used as references for the TDMS signals on the
module connector, it is recommended that 1nF stitching capacitors are added to the HPD and
100pF stitching capacitors to the CEC signal, close to the module connector.
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