Toradex Verdin - Verdin HDMI and DVI Interfaces

Verdin Carrier Board Design Guide
Preliminary – Subject to Change
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Verdin
Pin
Verdin
Signal Name
Recommended Termination
169
USB_2_SSTX_N
Leave NC if not used
185
USB_2_EN
Leave NC if not used
187
USB_2_OC#
Add pull-up resistor or disable the over-current function in software
Table 11: Unused USB signal termination
2.5 HDMI/DVI
The HDMI and DVI interface use a TMDS compatible physical link to transfer video and optional
audio data. Electrically, HDMI and DVI are equal, but there can be some differences in the
protocol. HDMI is the successor of DVI and specifies the additional transport for audio data and
content protection (HDCP). HDMI devices (monitor, television set etc.) can be driven with the DVI
interface as HDMI is backward compatible. Compatibility is not guaranteed when attempting to
drive a DVI device with an HDMI interface. Not all DVI displays accept the HDMI protocol or are
HDCP compatible. Please read the datasheet of the Verdin module for more information about the
supported HDMI and DVI protocols.
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. If you
are planning to implement HDMI in a final product, you need to check for the HDMI adopter
license.
2.5.1 HDMI/DVI Signals
Verdin
Pin
Verdin
Signal Name
I/O
Type
Power
Rail
Description
69
HDMI_1_TXC_P
O
TDMS
HDMI/DVI differential clock positive
67
HDMI_1_TXC_N
O
TDMS
HDMI/DVI differential clock negative
75
HDMI_1_TXD0_P
O
TDMS
HDMI/DVI differential data lane 0, positive
73
HDMI_1_TXD0_N
O
TDMS
HDMI/DVI differential data lane 0, negative
81
HDMI_1_TXD1_P
O
TDMS
HDMI/DVI differential data lane 1, positive
79
HDMI_1_TXD1_N
O
TDMS
HDMI/DVI differential data lane 1, negative
87
HDMI_1_TXD2_P
O
TDMS
HDMI/DVI differential data lane 2, positive
85
HDMI_1_TXD2_N
O
TDMS
HDMI/DVI differential data lane 2, negative
63
HDMI_1_CEC
I/O
OD
1.8V
HDMI consumer electronic control
61
HDMI_1_HPD
I
CMOS
1.8V
Hot Plug Detect
57
I2C_3_HDMI_SDA
I/O
OD
1.8V
I2C interface for reading the extended display identification data
(EDID) over DDC. This interface is shared with other display
interfaces
59
I2C_3_HDMI_SCL
O
OD
1.8V
Table 12: HDMI/DVI signals
2.5.2 Reference Schematics
2.5.2.1 DVI Schematic Example
There are different DVI connector configurations available. The DVI-D (digital) supports only the
native DVI signals. The DVI-A (analog) provides only analog VGA signals. The DVI-I (integrated)
combines the digital DVI signals and the analog 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.