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Digital display interfaces, Displayport / hdmi / dvi, Signal definitions – Kontron COMe Starterkit Eval T2 User Manual

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COM Express Interfaces

2.5.

Digital Display Interfaces

Module Types 6 and 10 use Digital Display Interfaces (DDI) to provide DisplayPort, HDMI/DVI,
and SDVO interfaces. Type 10 Modules can contain a single DDI (DDI[0]) that can support
DisplayPort, HDMI/DVI, and SDVO. Type 6 Modules can contain up to 3 DDIs (DDI[1:3]) of
which DDI[1:3] can support DisplayPort, HDMI/DVI and DDI[1] can support DisplayPort,
HDMI/DVI, and SDVO. The main difference is that SDVO is only supported on DDI[0] for Type
10 Modules and DDI[1] for Type 6 Modules.

Module Type 2 offers additionally the possibility to have SDVO shared with PEG.

2.5.1.

DisplayPort / HDMI / DVI

DisplayPort was developed by the Video Electronics Standard Association (VESA) in order to
create a new digital display port interface to connect a video source to a display device.

DisplayPort can be used to transfer audio and video at the same time, but each one is optional
and can be transmitted without the other. A bi-directional, half-duplex auxiliary channel carries
device management and device control data for the Main Link, such as VESA EDID.
DisplayPort is nowadays on almost all COM Express Modules available as Dual-mode
DisplayPort, that can directly emit single-link HDMI and DVI signals using an adapter, which
contains a level shifter to adjust for the lower voltages required by DisplayPort. These adapters
can be directly implemented on the Carrier Board to have an easy, simple and future proof
implementation of HDMI and/or DVI or an inexpensive cable adapter can be directly connected
on the Carrier Board's DisplayPort connector.

2.5.1.1.

Signal Definitions

Type 10 offers up to one DisplayPort interface and Type 6 Modules up to 3 DisplayPort
interfaces. Both implementations are very similar, so only one reference schematic is necessary
to show Carrier Board implementation.
Each DisplayPort interface consists of 4 differential lanes, 1 auxiliary lane and 1 hot-plug-detect
signal. The DDC_AUX_SEL pin should be routed to pin 13 of the DisplayPort connector, to
enable Dual-Mode. When HDMI/DVI is directly done on the Carrier Board, this pin shall be
pulled to 3.3V with a 100k Ohm resistor to configure the AUX pairs as DDC channels.

Table 11:

Display Port / HDMI / DVI Pin-out of Type 10 and Type 6

COM Express
Pin Name

DDI0
Type 10

DDI1
Type 6

DDI2
Type 6

DDI3
Type 6

Function (DDIX)
DisplayPort

Function (DDIX)
HDMI / DVI

DDIX_PAIR0+

B71

D26

D39

C39

DPX_LANE0+

TMDSX_DATA2+

DDIX_PAIR0-

B72

D27

D40

C40

DPX_LANE0-

TMDSX_DATA2-

DDIX_PAIR1+

B73

D29

D42

C42

DPX_LANE1+

TMDSX_DATA1+

DDIX_PAIR1-

B74

D30

D43

C43

DPX_LANE1-

TMDSX_DATA1-

DDIX_PAIR2+

B75

D32

D46

C46

DPX_LANE2+

TMDSX_DATA0+

DDIX_PAIR2-

B76

D33

D47

C47

DPX_LANE2-

TMDSX_DATA0-

DDIX_PAIR3+

B81

D36

D49

C49

DPX_LANE3+

TMDSX_CLK+

DDIX_PAIR3-

B82

D37

D50

C50

DPX_LANE3-

TMDSX_CLK-

DDIX_HPD

B89

C24

D44

C44

DPX_HPD

HDMIX_HPD

DDIX_CTRLCLK_AUX+

B98

D15

C32

C36

DPX_AUX+

HDMIX_CTRLCLK

DDIX_CTRLDATA_AUX-

B99

D16

C33

C37

DPX_AUX-

HDMIX_CTRLDATA

DDIX_DDC_AUX_SEL

B95

D34

C34

C38

Note:

Please verify in the Module's specification if DisplayPort or Dual-Mode
DisplayPort is supported.

PICMG

®

COM Express

®

Carrier Board Design Guide

Rev. 2.0 / December 6, 2013

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