Daewoo DDT-21H9ZDF(21"), Service Manual

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The signal read from DVD disc is output into the RFsignal and Servo related signal through the RF IC and
they are input into the MPEG decoder and processed the MPEG decoding and divided into video/audio signal.
The video signal is output into the analog audio signal through the built-in encoder block and also the audio
signal into the audio DAC through the audio decoder block.
MPEG decoder consists of existing MPEG-2 decoder and single chip combined the digital signal
processing part which is the core technology of DVD player with the Servo controller
1) DVD Servo and MPEG-2 Decoder : M3351 (IC01)
M3351 is single chip combined the front-end consisting of DVD decoder, CD/CD-ROM decoder, data
channel, digital servo controller with the back-end consisting of RISC CPU, MPEG A/V decoder, TV
encoder, TV DAC, Audio ADC. The role of the front-end is to demodulate the regenerated signal input
through the RF IC, to correct errors and to control the variable bit rate and then to separate each
stream of video/audio and finally to output into the back-end which links the decoder block. As for CD,
the signal processing is different from that of DVD. The Servo error signal of RF IC and the Servo
control monitoring signal is input in the digital servo block and outputs into the spindle, the sled, the
tray motor control signal, the focus and tracking signal for the pick-up actuator control.
The decoded video signal is transferred into the analog audio signal for the display on the TV
encoder(Composite, S-VIDEO, Component and etc.) after adding sub-picture and OSD scene.
Although the RISC CPU belongs to the back-end, it plays the major role in generalizing and
controlling the whole system operation of DVD player.
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CIRCUIT OPERATIONAL DESCRIPTION
M3351 DVD Servo and MPEG-2 Decoder Block Diagram
MPEG Decoder