Apalis Carrier Board Design Guide
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The HDMI and DVI interfaces define different connectors. There are passive adapters available in
both directions. Please be aware that HDMI and HDCP have licensing restrictions in place.
2.8.1
HDMI/DVI Signals
Apalis
Pin
Apalis
Signal Name
I/O
Type
Power
Rail
Description
240
HD
O
TDMS
HDMI/DVI differential clock positive
242
HDMI1_TXC-
O
TDMS
HDMI/DVI differential clock negative
234
HDM
O
TDMS
HDMI/DVI differential data lane 0 positive
236
HDMI1_TXD0-
O
TDMS
HDMI/DVI differential data lane 0 negative
228
HDM
O
TDMS
HDMI/DVI differential data lane 1 positive
230
HDMI1_TXD1-
O
TDMS
HDMI/DVI differential data lane 1 negative
222
HDM
O
TDMS
HDMI/DVI differential data lane 2 positive
224
HDMI1_TXD2-
O
TDMS
HDMI/DVI differential data lane 2 negative
220
HDMI1_CEC
I/O
OD
3.3V
HDMI consumer electronic control
232
HDMI1_HPD
I
CMOS
3.3V
Hot-plug detect
205
I2C2_SDA
I/O
OD
3.3V
I
2
C interface for reading the extended display identification data (EDID)
over DDC. This interface is shared with other display interfaces
207
I2C2_SCL
O
OD
3.3V
Table 17: HDMI/DVI signals
2.8.2
Reference Schematics
2.8.2.1
DVI Schematic Example
There are different DVI connector configurations available. The DVI-D (digital) supports only the
native DVI signals. The DVI-A (analogue) provides only analogue VGA signals. The DVI-I
(integrated) combines the digital DVI signals and the analogue VGA signals. For the DVI-A and
DVI-I, there are passive adapters to the D-SUB VGA connector available. There is only one DDC
channel available on the DVI-I interface. Therefore, the connector is not designed to use both links
(DVI and VGA) simultaneously. Nevertheless, there are Y-cables available which provide a DVI and
VGA output. Such cables are not standardized. They provide the DDC on either the DVI or VGA
output. Please be aware of this when using a similar Y-cable.
The following schematic example shows a DVI-I implementation. It can be used as an example for
a DVI-D design if you simply remove the analogue VGA signals. The sync signals for the VGA
signals need to be level shifted from 3.3V to 5V. The same is necessary for the DDC signals. The
TDMS signals need to be ESD protected using diodes. The schematic example shows a discrete
solution for the level shifting and protection. There are integrated solutions also available.