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COM Express® Carrier Board Design Guide
2.3.2 SDVO
2.3.2.1 Signal Definitions
Type 6 Modules allow one SDVO port on DDI[1]. The DDI port needs to be configured to be used
as SDVO usually via the Module's BIOS.
On Type 2 Modules the pins for SDVO ports B and C are shared with the PEG port.
Table 3: SDVO Port Configuration
SDVO Port B
SDVO Port C
Device Type
Selectable in BIOS Setup Program.
Selectable in BIOS Setup Program.
I²C Address
0111 000x
0111 001x
I²C Bus
SDVO I²C GPIO pins
SDVO I²C GPIO pins
DDC Bus
SDVO I²C GPIO pins
SDVO I²C GPIO pins
2.3.2.2 Reference Schematics
Figure 9: SDVO to DVI Transmitter Example
Please refer to:
PICMG COM Express Carrier Board Design Guide
Rev. 2.0 / December 6, 2013
Page 59, Figure 22: DVI Example
2.3.2.3 Routing Considerations
DVI is based on the differential signaling method TDMS. The TDMS differential signals between
the SDVO to DVI transmitter and the DVI connector have to be routed in pairs with a differential
impedance of 100Ω. The length of the differential signals must be kept close. The length difference
must within 100mils for any of the pairs relative to each other. Spacing between the differential pair
traces should be over 2x the trace width to reduce trace-to-trace couplings. Having wider gaps
between differential pair DVI traces will reduce noise coupling. Ground should not be placed
adjacent to the DVI traces on the same layer. Keep a distance of at least 30mils between the DVI
trace and any ground on the same layer.
Summary of Contents for ET976
Page 1: ...COM EXPRESS CARRIER BOARD DESIGN GUIDE Version 1 0 January 2022...
Page 11: ...COM Express Carrier Board Design Guide 5 Figure 3 PCI Express x4 Slot Example...
Page 12: ...6 COM Express Carrier Board Design Guide Figure 4 PCIe Mini Card Reference Circuitry...
Page 19: ...COM Express Carrier Board Design Guide 13 Figure 7 HDMI Example 1...
Page 20: ...14 COM Express Carrier Board Design Guide Figure 7 HDMI Example 2...
Page 21: ...COM Express Carrier Board Design Guide 15 Figure 8 DVI Example 1...
Page 22: ...16 COM Express Carrier Board Design Guide Figure 8 DVI Example 2...
Page 31: ...COM Express Carrier Board Design Guide 25 Figure 12 USB 3 0 Example 2...
Page 37: ...COM Express Carrier Board Design Guide 31 Figure 14 LVDS Reference Schematic 2...
Page 44: ...38 COM Express Carrier Board Design Guide Figure 16 VGA Reference Schematics 2...
Page 48: ...42 COM Express Carrier Board Design Guide Figure 18 HDA Example Schematic 2...
Page 52: ...46 COM Express Carrier Board Design Guide Figure 19 LPC Super I O Example 2...
Page 61: ...COM Express Carrier Board Design Guide 55 Figure 24 General Purpose Serial Port Example 2...
Page 70: ...64 COM Express Carrier Board Design Guide Figure 28 PWRBTN and SYS_RESET Circuitry...
Page 84: ...78 COM Express Carrier Board Design Guide Chapter 4 Carrier Board PCB Layout Guidelines...
