Philips DPTV400 Series, Руководство по обучению

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AV3 and AV4 Inputs and Switching (Figure 23)
The input to AV3 can be either in the Y Pb Pr or RGB formats. The sync for the RGB format can be
separate Horizontal and Vertical or Sync on Green. The Component Y Pb Pr connected to AV3 or
AV4 can be a 1 fH (480i), 2 fH (480p), 720p, or 1080i signal. Component Y Pb Pr or RGB can also
be connected to AV4. An RGB signal must have Sync on Green for this input. There are no sepa-
rate Horizontal and Vertical sync inputs for AV4.
IC 7100 selects Component video or RGB from AV3 or AV4. IC7100 is controlled by the HD_SEL
control line from the HD_DW processor, 7700.
IC 7400 is an A/D (Analog to Digital converter), Sync processor, and Video switch. The IC selects
between the output of 7100 and the Y Pb Pr signals from the YUV to Y Pb Pr converter. The
Clamping circuit sets the sampling point and amplitude of the incoming signal before feeding it to the
A/D converter. The signal sampling Offset and Drive levels are set in the SAM menu which are
explained in the adjustment section. The output of the A/D converters is fed to the Scaler on three
eight bit data lines. These Data lines are shared with those from the HDMI receiver. When the
HDMI receiver is switched On, the data lines are switched Off becoming open circuits.
If the Sync of the applied signal is Sync on Green or Sync on Y, the Y or Green signal on Pin 30 is
fed to the Scaler IC for Sync detection. If separate Horizontal and Vertical Sync is applied to AV3
and AV3 is selected, it is output on Pins 22 and 21. Vertical Sync is fed to Pin 42 of 7400.
Horizontal Sync is fed to 7401-A. If separate Horizontal and Vertical Sync is present, the Processor
on the HD_DW panel will switch the H-RGB_SEL line High, switching the Horizontal Sync to Pin 43
of 7400. The Sync is processed and output on Pins 125 and 127.
IC 7400 is controlled by the SDA_MP and SCL_MP date line from the Microprocessor, 7700, located
on the HD_DW panel.
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