VIA Technologies SOM-9X35, Design Manual, Page: 39 / 81

Carrier Board Design Guide for SOM-9X35 Module
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4. Layout & Routing Recommendation
The information presented in this chapter includes the signal definition, topology, layout and routing guidelines
for each bus interface, and reference schematics example. The information provided is intended for designing
carrier boards that are compliant with the SOM-9X35 module.
4.1 HDMI Interface
The SOM-9X35 module features one HDMI interface. The HDMI interface uses four control signals, one
differential clock, and three differential data pair signals that carry video and audio signals.
4.1.1 HDMI Signal Definition
Signal
Name
Pin #
Pad Characteristics
Description
Voltage Type
TX _CLK_M J2.57 AO HDMI differential clock – minus
TX _CLK_P J2.55 AO HDMI differential clock –plus
TX _CH0_M J2.51 AO HDMI differential transmit 0 – minus
TX _CH0_P J2.49 AO HDMI differential transmit 0–plus
TX _CH1_M J2.45 AO HDMI differential transmit 1 – minus
TX _CH1_P J2.43 AO HDMI differential transmit 1–plus
TX_CH2_M J2.41 AO HDMI differential transmit 2 – minus
TX_CH2_P J2.39 AO HDMI differential transmit 2–plus
TX_CEC J1.1 3.3V B-PU HDMI consumer electronics control configurable I/O
TX_DDCSCL J1.3 5V B-PU HDMI display data channel – clock configurable I/O
TX_DDCSDA J1.5 5V B-PU HDMI display data channel – data configurable I/O
TX_HPD J1.4 5V B-PD HDMI hot plug detect configurable I/O
Table 07: HDMI signal definition
Route Differen�ally
Route Differen�ally
Route Differen�ally
Route Differen�ally
HDMI
connector
SOM-9X35
M.2 Slot
Edg
e fing
er
HDMI_TX0_P
HDMI_DDC CLK
HDMI_DDC_DATA
HDMI_CEC
HDMI_HPLUG_DET
HDMI_TCLK_M
HDMI_TX0_M
HDMI_TX1_P
HDMI_TX1_M
HDMI_TX2_P
HDMI_TX2_M
HDMI_TCLK_P
ESD protec�on
and
Overcurrent
protec�on
IC
Figure 37: HDMI routing topology