DS90UH925Q Datasheet, PDF (20/47 Pages) Texas Instruments – 720p 24-bit Color FPD-Link III Serializer with HDCP

DS90UH925Q
HDCP
The Cipher function is implemented in the serializer per HDCP v1.3 specification. The DS90UH925Q provides HDCP encryption
of audiovisual content when connected to an HDCP capable FPD-Link III deserializer such as the DS90UH926Q. HDCP authen-
tication and shared key generation is performed using the HDCP Control Channel which is embedded in the forward and backward
channels of the serial link. An on-chip Non-Volatile Memory (NVM) is used to store the HDCP keys. The confidential HDCP keys
are loaded by TI during the manufacturing process and are not accessible external to the device.
The DS90UH925Q uses the Cipher engine to encrypt the data as per HDCP v1.3. The encrypted data is transmitted through the
FPD-Link III interface.
HDCP REPEATER
When DS90UH925Q and DS90UH926Q are configured as the HDCP Repeater application, it provides a mechanism to extend
HDCP transmission over multiple links to multiple display devices. This repeater application provides a mechanism to authenticate
all HDCP Receivers in the system and distribute protected content to the HDCP Receivers using the encryption mechanisms
provided in the HDCP specification.
Repeater Configuration
In HDCP repeater application, In this document, the DS90UH925Q is referred to as the HDCP Transmitter or transmit port (TX),
and the DS90UH926Q is referred to as the HDCP Receiver (RX). Figure 12 shows the maximum configuration supported for HDCP
Repeater implementations using the DS90UH925Q (TX) and DS90UH926Q (RX). Two levels of HDCP Repeaters are supported
with a maximum of three HDCP Transmitters per HDCP Receiver.
FIGURE 12. HDCP Maximum Repeater Application
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To support HDCP Repeater operation, the DS90UH926Q Deserializer includes the ability to control the downstream authentication
process, assemble the KSV list for downstream HDCP Receivers, and pass the KSV list to the upstream HDCP Transmitter. An
I2C master within the DS90UH926Q communicates with the I2C slave within the DS90UH925Q Serializer. The DS90UH925Q
Serializer handles authenticating with a downstream HDCP Receiver and makes status available through the I2C interface. The
DS90UH926Q monitors the transmit port status for each DS90UH925Q and reads downstream KSV and KSV list values from the
DS90UH925Q.
In addition to the I2C interface used to control the authentication process, the HDCP Repeater implementation includes two other
interfaces. A parallel LVCMOS interface provides the unencrypted video data in 24-bit RGB format and includes the DE/VS/HS
control signals. In addition to providing the RGB video data, the parallel LVCMOS interface communicates control information and
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