HDCP 1.4 Key Input Interface (AXI4-Stream Slave Interface) - 3.2 English

HDMI 1.4/2.0 Transmitter Subsystem Product Guide (PG235)
Document ID
PG235
Release Date
2023-10-18
Version
3.2 English

The following table shows the signals for HDCP 1.4 key interface. This interface runs at the hdcp14_key_aclk (which is running at the AXI4-Lite clock).

Table 1. HDCP 1.4 Key Input Interface
Name I/O Width Description
HDCP_KEY_IN_tdata I 64 HDCP 1.4 key data
HDCP_KEY_IN_tlast I 1 End of key data
HDCP_KEY_IN_tready O 1 Ready
HDCP_KEY_IN_tuser I 8 Start of key data
HDCP_KEY_IN_tvalid I 1 Valid
hdcp14_key_aclk O 1 AXI4-Stream clock
hdcp14_key_aresetn O 1 Reset (Active-Low)
hdcp14_start_key_transmit O 1 Start key transmit
hdcp14_reg_key_sel O 3 Key select

For the HDCP 1.4 transmitter, an HDCP Key Management module is needed, which is able to send keys over the AXI4-Stream interface to the HDCP 1.4 controller. The following figure shows an example of how the HDMI 1.4/2.0 TX Subsystem is connected to the HDCP Key Management module through a Key Management Bus (AXI4-Stream). The HDCP Key Management module is not part of the HDMI 1.4/2.0 TX Subsystem. For HDCP 1.4 design details, see the HDCP 1.x Product Guide (PG224).

Figure 1. HDCP 1.4 Key Management Bus (AXI4-Stream)

However, the HDCP 2.3 key is handled slightly differently as it is solely controlled by the software application. The user application is responsible for providing the infrastructure to securely store and retrieve the keys to be loaded into the HDCP 2.3 drivers. For the detailed list of keys that are required to be loaded by the user application, see the HDCP 2.2 LogiCORE IP Product Guide (PG249).