Daewoo DUB-2850GB Service Manual page 53

CP-780 Service Manual
The digital controller sound part consists of the SSIFADC, audio ADCs, DEMDEC HW, the
sound DSP core, audio DACs and I2S interface hardware as shown in fig below. The DEMDEC
part of the Sound DSP is used for the decoder and partly demodulator tasks. The AUDIO part
provides the sound features, from the level adjust unit up to the output crossbar. Audio DACs
and I2S hardware are converting the processed signals to analogue or digital audio.
The SSIF signal is applied to the SSIF ADC for conversion and is then fed to the DEMDEC
hardware processing mainly for demodulation but also some decoding tasks. Remaining
decoding is done in the DEMDEC block of the Sound DSP. The DEMDEC processing will be
described in the next chapter.
The audio signals (AUD ADC IN) from the analogue crossbar pass the audio ADC and are fed
directly into the AUDIO part of the Sound DSP like the I2S signals, which is coming from I2S
processing hardware. After level adjust all signals from the DEMDEC and the I2S input are
available at the digital input crossbar. A special input is provided for the Noise/Silence
Generator needed for Dolby(r) Pro Logic(r) processing.
In standard TV applications the main channel signal(L,R) will be connected to the DAC2 for
reproduction at the speakers. With multichannel signals centre, surround or subwoofer
channels may be passed to the I2S outputs where external DACs may be applied. By this it is
possible to build Dolby Normal/Wide, Dolby Phantom Centre or Dolby 3 Stereo set-ups and
also a VDS423 application.
5.4.3 Demodulator and decoder
INTRODUCTION
The TV sound processor provides an easy-to-use programming interface and built-in
intelligence for the demodulator and decoder part.
The sound demodulator is able to search for sound carriers and react to transmission mode
changes autonomously, without interaction of the micro controller software.
It is possible for a typical terrestrial TV application to setup the entire demodulator with
transmission of few control words.
The control interface still allows access to every detail, called demodulator expert mode, for
special applications such as satellite TV, more elaborated search algorithms etc.
The new TV Sound Processor Demodulator and Decoder Easy Programming(DDEP) interface
provides three possible approaches to setup the demodulator and decoder parts:
* Auto Standard Detection (ASD)
* Static Standard Selection (SSS)
* Demodulator and Decoder Expert Mode (DDXM)
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