As part of the HDMI 2.1 TX Subsystem, the AMD LogiCORE IP High-bandwidth Digital Content Protection (HDCP) transmitters are designed to transmit audiovisual content securely between two devices that are HDCP capable. In this HDMI 2.1 TX Subsystem, both HDCP 1.4 and HDCP 2.3 transmitter IP cores are included, and can be enabled by the HDCP option in the Vivado IDE.
As a guideline, in FRL mode, all contents are protected with HDCP 2.3. On the other hand, in TMDS mode, HDCP 2. encrypts content at Ultra-High Definition (UHD) while HDCP 1.4 is the legacy content protection scheme for lower resolutions backward compatible with HDCP 1.4 only sinks.
The following figure shows the HDMI TX configuration enabling both HDCP 1.4 and 2. With both HDCP protocols enabled, the HDMI Subsystem configures itself in the cascade topology connecting the HDCP 1.4 and HDCP 2.3 back-to-back. The HDCP Egress interface of the HDMI transmitter sends unencrypted audiovisual data, which the active HDCP block is encrypts and sends back into the HDMI transmitter over the HDCP Ingress interface for transmission over the link. The HDMI TX Subsystem ensures only one active HDCP protocol at any given time, rendering the other passive by calling the relevant HDMI 2.1 TX Subsystem API functions.
For more details on HDCP, see the HDCP 1.x Product Guide (PG224) and the HDCP 2.2 LogiCORE IP Product Guide (PG249).