Cambridge Audio Azur 752BD Service Manual page 14

Video output
Video output signals are classified into 3 types:
Analog output: Video signal is converted into analog video signal (CVBS) by the DAC built in
Mt8580, then processed by video amplification and filter cirucits, output through the diagnostic port to
a display with composite video input port for troubleshooting.
HDMI output: The digital video interface of MT8580 transmits digital video signal to
MARVELL88DE2755 HD video processing chip for format conversion, in which the digital video signal
is converted into 36 bit digital video signal. Then the parallel 36bit video signal is encoded into TMDS
signal, and in the mean time digital audio signal output from Mt8530 is also endoded into TMDS.
88DE2755 also has HDCP encryptor built in. The TMDS signal output from 88DE2755 is transmitted to
HDMI 1 for output. For protection of HDMI 1 port, the circuit also has anti-ESD IC included. For HDMI 2,
video signal is processed into HDMI signal by the MTDS circuit built in Mt8580 and output via HDMI 2
output port.
Video output circuit issues mainly include no video output and output video signal distortion.
HDMI/MHL input
Mt8580 incorporates two sets of HDMI input; one HDMI input port locates on the rear panel and
goes directly into MT8580's HDMI input port. For compatibility with MHL port of mobile device, a
MHL/HDMI conversion IC (sil1292) is added to the other HDMI input port (on the front panel).
Mobile High-Definition Link (MHL) is a proposed industry standard for a mobile audio/video
interface for directly connecting mobile phones and other portable consumer electronics (CE) devices to
high-definition televisions (HDTVs) and displays. The MHL standard features a single cable with a low
pin-count interface able to support up to 1080p high-definition (HD) video and digital audio while
simultaneously charging the connected device
New features of HDMI 1.4
1. HDMI Ethernet Channel (HEC). It allows a 100 Mbit/s Ethernet connection between two HDMI
connected devices so they can share an Internet connection. This feature hasn't been implemented on
BDP103.
2. Audio Return Channel (ARC). BDP103 has implemented this feature.
3. HDMI 3D. BDP103 has enabled this feature as well as 2D-to-3D conversion.
4. Higher resolution support. HDMI 1.4 increases maximum resolution support to 4K × 2K, i.e.
3840 × 2160p (Quad HD) at 24 Hz/25 Hz/30 Hz or 4096 × 2160p at 24 Hz
14
-12-