Seco Qseven QuadMo747 x2000 User Manual page 36

3.2.3.9 HDMI interface signals
As told in the previous paragraph, the Intel
modes.
Digital Display Interface #0, in particular, is used to implemented HDMI or Multimode Display Port interface.
Please be aware that the board is factory configured to have HDMI or Multimode Display Port interface.
If the board purchased is in HDMI configuration, then voltage level shifters on the carrier board are not necessary (they can also interfere with
regular working of the board). Please take care of specifying if you need HDMI interface or DP when placing an order of QuadMo747-x2000
module.
Signals involved in HDMI management are the following:
TMDS_CLK+/TMDS_CLK-: TMDS differential Clock.
TMDS_TX0+/TMDS_TX0-: TMDS differential pair #0.
TMDS_TX1+/TMDS_TX1-: TMDS differential pair #1.
TMDS_TX2+/TMDS_TX2-: TMDS differential pair #2.
HDMI_CTRL_DAT: DDC Data line for HDMI panel. Bidirectional signal, electrical level +3.3V_S with a 2k2Ω pull-up resistor. Also used as a strap signal for the
QuadMo747-x2000 module (please check par. 3.2.4 for further details).
HDMI_CTRL_CLK: DDC Clock line for HDMI panel. Bidirectional signal, electrical level +3.3V_S with a 2k2Ω pull-up resistor.
HDMI_CEC: HDMI Consumer Electronics Control (CEC) Line. Bidirectional signal, electrical level +3.3V_S. According to Qseven
reality, a General Purpose 1_wire bus interface, that can be used for implementation of HDMI_CEC. Real usage of this signal depends on QuadMo747-x2000
dedicated API libraries.
DP_HDMI_HPD#: Hot Plug Detect Input signal. +3.3V_S electrical level signal, active low with 100kΩ pull-up resistor. Please consider that HDMI specification
assume that the Hot Plug signal is active high, and at +5V_S level. An inverting voltage level shifter is therefore needed on the Carrier board to ensure the working
of HDMI port.
Please be aware that it is not necessary to implement voltage level shifter for TMDS differential pairs on the Carrier board, but such level shifters are still necessary
on Control data/Clock signals, as well as for Hot Plug Detect signal.
Voltage clamping diodes are also highly recommended on all signal lines for ESD suppression.
Please refer to the following schematics as an example of implementation of HDMI connection + voltage level shifters on the carrier board.
QuadMo747-x2000
QuadMo747-x2000 User Manual - Rev. First Edition: 1.0 - Last Edition: 2.0 - Author: S.B. - Reviewed by G.G. Copyright © 2014 SECO S.r.l.
®
Atom Cedarview family of CPUs offer two Digital Display Interfaces, configurable to work in HDMI/DVI/DP++/eDP
®
specifications, the signal is, in
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