HDCP data transmission over a single communication channel

A method for transmitting control data between a high-bandwidth digital content protection (HDCP) transmitting device and an HDCP receiving device via a transmitter and a receiver configured to communicate with each other over a single, duplex communication channel, the method comprising:

• the transmitter receiving from the HDCP transmitting device a read transaction request for HDCP control data and a clock signal via a first serial bus including at least a first signal line dedicated for transmitting the clock signal and a second signal line for transmitting the HDCP control data, the read transaction request including an address of the HDCP receiving device;
• the transmitter sending to the receiver over the single, duplex communication channel the read transaction request for the HDCP control data;
• the transmitter stretching the clock signal until the requested HDCP control data is received by the transmitter;
• the transmitter receiving from the receiver over the single, duplex communication channel the requested HDCP control data without the clock signal, wherein the single, duplex communication channel does not have a dedicated clock signal line and is not capable of carrying the clock signal and the HDCP control data at the same time;
• the transmitter releasing the clock signal;
• and
• the transmitter providing to the HDCP transmitting device the HDCP control data via the first serial bus in response to the read transaction request.

A method for transmitting control data between a high-bandwidth digital content protection (HDCP) transmitting device and an HDCP receiving device via a transmitter and a receiver configured to communicate with each other over a single, duplex communication channel, the method comprising:

• the receiver issuing a read command request for HDCP control data to the HDCP receiving device via a first serial bus including at least a first signal line dedicated for transmitting a clock signal and a second signal line for transmitting the HDCP control data, the request including an address of the HDCP receiving device;
• the receiver receiving the requested HDCP control data from the HDCP receiving device via the first serial bus;
• the receiver providing the received HDCP control data over the single, duplex communication channel to the transmitter without the clock signal, wherein the single, duplex communication channel does not have a dedicated clock signal line and is not capable of carrying the clock signal and the HDCP control data at the same time;
• the transmitter receiving from the HDCP transmitting device a read transaction request for the HDCP control data via a second serial bus including at least a third signal line dedicated for transmitting the clock signal and a fourth signal line for transmitting the HDCP control data;
• and
• the transmitter providing the previously received HDCP control data to the HDCP transmitting device via the second serial bus.

A communication device for facilitating the transmission of control data between a high-bandwidth digital content protection (HDCP) transmitting device and an HDCP receiving device over a single, duplex communication channel, the communication device comprising:

• a transmitter adapted to:
• receive from the HDCP transmitting device a read transaction request for HDCP control data and a clock signal via a first serial bus including at least a first signal line dedicated for transmitting the clock signal and a second signal line for transmitting the HDCP control data, the request including an address of the HDCP receiving device,
• stretch the clock signal until the requested HDCP control data is received at the transmitter,
• receive from a receiver over the single, duplex communication channel the requested HDCP control data without the clock signal, wherein the single, duplex communication channel does not have a dedicated clock signal line and is not capable of carrying the clock signal and the HDCP control data at the same time,
• release the clock signal, and
• provide the HDCP control data to the HDCP transmitting device via the first serial bus;
• and
• the receiver adapted to receive the HDCP control data from the HDCP receiving device via a second serial bus including at least a third signal line dedicated for transmitting the clock signal and a fourth signal line for transmitting the HDCP control data and to provide the received HDCP control data to the transmitter without the clock signal over the single, duplex communication channel.

A communication device for facilitating the transmission of control data between a high-bandwidth digital content protection (HDCP) transmitting device and an HDCP receiving device over a single, duplex communication channel, the communication device comprising:

• a transmitter adapted to:
• receive from the HDCP transmitting device a read transaction request for HDCP control data via a first serial bus including at least a first signal line dedicated for transmitting a clock signal and a second signal line for transmitting the HDCP control data,
• send a negative acknowledgment signal to the HDCP transmitting device via the first serial bus, responsive to the transmitter not having received the requested HDCP control data,
• receive from the HDCP transmitting device a retry read request for the HDCP control data via the first serial bus, and
• provide the HDCP control data to the HDCP transmitting device via the first serial bus after having received the requested HDCP control data without the clock signal from a receiver over the single, duplex communication channel, wherein the single, duplex communication channel does not have a dedicated clock signal line and is not capable of carrying the clock signal and the HDCP control data at the same time;
• and
• the receiver adapted to receive the HDCP control data from the HDCP receiving device via a second serial bus including at least a third signal line dedicated for transmitting the clock signal and a fourth signal line for transmitting the HDCP control data and to provide the HDCP control data to the transmitter without the clock signal over the signal, duplex communication channel.

A communication device for facilitating the transmission of control data between a high-bandwidth digital content protection (HDCP) transmitting device and an HDCP receiving device over a single, duplex communication channel, the communication device comprising:

• a first communication device adapted to perform the steps of:
• issuing, to the HDCP receiving device, a read command request for HDCP control data, via a first serial bus including at least a first signal line dedicated for transmitting a clock signal and a second signal line for transmitting the HDCP control data,
• receiving the requested HDCP control data via the first serial bus, and
• providing the received HDCP control data without the clock signal over the single, duplex communication channel to a second communication device;
• and
• the second communication device adapted to perform the steps of:
• receiving the HDCP control data without the clock signal from the first communication device over the single, duplex communication channel, wherein the single, duplex communication channel does not have a dedicated clock signal line and is not capable of carrying the clock signal and the HDCP control data at the same time,
• receiving, from the HDCP transmitting device, a read transaction request for the HDCP control data via a second serial bus including at least a third signal line dedicated for transmitting the clock signal and a fourth signal line for transmitting the HDCP control data, and
• providing the previously received HDCP control data to the HDCP transmitting device via the second serial bus.

A method for facilitating the transmission of control data between a high-bandwidth digital content protection (HDCP) transmitting device and an HDCP receiving device via a first communication device and a second communication device configured to communicate with each other over a single, duplex communication channel, the method comprising:

• the first communication device receiving from the HDCP transmitting device a write transaction request via a first serial bus including at least a first signal line dedicated for transmitting a clock signal and a second signal line for transmitting the HDCP control data, the request including an address of the HDCP receiving device;
• the first communication device building a data packet that includes HDCP control data;
• the first communication device sending the data packet without the clock signal over the single, duplex communication channel to the second communication device, wherein the single, duplex communication channel does not have a dedicated clock signal line and is not capable of carrying the clock signal and the HDCP control data at the same time;
• the second communication device receiving the data packet;
• and
• the second communication device issuing a write command to the HDCP receiving device via a second serial bus including at least a third signal line dedicated for transmitting the clock signal and a fourth signal line for transmitting the HDCP control data, the write command including the HDCP control data.