The transistors will be off when the board is not powered (isolating the CC pins from the connector) and on
when the board is powered (connecting the pins to the connector). For more details, see https://www.nxp.com/docs/en/
errata/ES_PTN5110NTHQ.pdf.
3.13 HDMI/display port connectivity (i.MX8 QM)
The i.MX8 QM provides an HDMI transmitter capable of supporting an HDMI2.0-compatible output, a Display Port-1.3 compatible
output, or an embedded Display Port 1.4-compatible output.
The connectivity to the i.MX8 QM is different, depending on whether the HDMI or the DP is implemented. Figure 31 shows the
Display Port connectivity of the i.MX8 QM, while Figure 32 shows the HDMI connectivity. For the HDMI output, note that there are
604 Ω resistors on the positive and negative sides of each high-speed output pair that are grounded through a FET. The gate to this
FET should be tied to the 1.8 V power for the HDMI transmit circuitry (VDD_HDMI_TX0_1P8, ball AW17). This will disconnect the
resistors automatically when the HDMI transmit circuitry is powered down. The resistors are required if the signals are connected
to a connector. If the signals are connected to another IC instead (serializer), usage of the resistors may not be needed or allowed.
Please consult the datasheet of the IC or its vendor for further reference.
Note that Figure 31 and Figure 32 do not show the optional circuitry (common mode chokes).
The HDMI input/output interfaces are not available on the i.MX8 QXP device.
Note: The Display Port silicon IP natively supports the DisplayPort Dual Mode (DP++). There are no current plans to support this
functionality in the BSP or to validate this feature in the silicon.
Figure 31. Display Port output connectivity
NXP Semiconductors
i.MX8 layout/routing recommendations
i.MX8 QM / i.MX8 QXP Hardware Developer’s Guide, Rev. 2.4p, 06/2021
User's Guide 67 / 89
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