User manual

CN3301, a connector that resembles a DVI port, is designed to receive digital video

from the receiver box. The HDCP (High-bandwidth Digital Content Protection) circuit

monitors the applied signals for copyright protection. Serial data that originates in the

receiver box is converted to parallel by IC3303, and back to serial by IC3305. This is

done to remove noise that may have been introduced into the long cable that connects

the receiver box and the display unit.

Clock and data output by IC3305 are applied to an I

C bus repeater circuit (IC3307)

before being applied to the EEPROM IC3308. The EEPROM contains the HDCP keys

used to block or allow the display of the content of a particular program. Data

communication is bi-directional allowing a complete handshake to take place before a

program is viewed.

The DR-board also performs sync selection of the input signals. Horizontal and vertical

sync of the tuner socket are directly connected to the sync select IC, IC3311. Sync

signals of the video input port are retrieved by IC3304 and provided to IC3311. The

output of the sync select switch is applied to the J-board via pins A30 and A32 of the

connector CN3303/J1.