The subsystem supports the Hot Plug Detect (HPD) feature, which is a communication mechanism between the HDMI source and HDMI sink devices. For example, when an HDMI cable is inserted between the HDMI source and sink devices, the HPD signal is asserted, which triggers the subsystem to start communicating with the sink device.
Important: The HPD
from HDMI Sink is at 5V. Therefore, a level shifter is required before connecting it to
the corresponding FPGA input pin in the HDMI 1.4/2.0 TX Subsystem design. For
example, if the HPD pin of the HDMI 1.4/2.0 TX Subsystem is at 3.3V bank, a
level shifter is required to translate HPD signal from 5V to 3.3V.