Digital display interfaces, Displayport / hdmi / dvi, Signal definitions – Kontron COMe Starterkit Eval T2 User Manual
Page 55
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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