As part of the HDMI 1.4/2.0 RX Subsystem, the AMD LogiCORE™ IP High-bandwidth Digital Content Protection (HDCP™) receivers are designed to receive audiovisual content securely between two devices that are HDCP capable. In this HDMI 1.4/2.0 RX Subsystem, both HDCP 1.4 and HDCP 2.3 receiver IP cores are included and can be enabled by the HDCP option in the Vivado IDE. However because HDCP 2.3 supersedes the HDCP 1.4 protocol and does not provide backwards compatibility, you need to decide and choose targeted content protection schemes from the Vivado IDE. Four different options are available to choose from:
- No HDCP
- HDCP 1.4 only
- HDCP 2.3 only
- HDCP 1.4 and HDCP 2.3
As a guideline, HDCP 2.3 is used to decrypt content at Ultra-High Definition (UHD) while HDCP 1.4 is the legacy content protection scheme used at lower resolutions.
The following figure shows a configuration of the HDMI RX where both HDCP 1.4 and 2.3 are enabled. With both HDCP protocols enabled, the HDMI Subsystem configures itself in the cascade topology where the HDCP 1.4 and HDCP 2.3 are connected back-to-back. The HDCP Egress interface of the HDMI receiver sends encrypted audiovisual data, which is decrypted by the active HDCP block and sent back into the HDMI receiver over the HDCP Ingress interface to send to other video processing modules in the system through AXI4-Stream Video interface or Native Video interface.
The HDMI 1.4/2.0 RX Subsystem automatically handles HDCP protocol switching when both HDCP 1.4 and HDCP 2.3 protocols are included in the subsystem. Automatic protocol switching is comprised of protocol detection and protocol enablement. The protocol is detected based on the incoming DDC read/write transaction to the HDCP DDC slave device with address 0x74. The HDCP DDC slave is partitioned into a HDCP 1.4 section (0x00 through 0x44) and a HDCP 2.3 section (0x50 through 0xC0). The HDMI receiver subsystem detects the protocol based on which section of the HDCP DDC slave is accessed. Upon a protocol detection event, an interrupt is generated and the interrupt service routine disables and resets both protocols, then enable the detected protocol. The entire detection and enablement procedure is transparent to the user application. When the HDMI receiver subsystem includes only a single HDCP protocol, this procedure is not required.
For more details on HDCP, see the HDCP 1.x Product Guide (PG224) and the HDCP 2.2 LogiCORE IP Product Guide (PG249).