STV2310D STMicroelectronics, STV2310D Datasheet - Page 28

• Manufacturer Part Number: STV2310D
• Description: Video ICs Digital Video Decodr
• Manufacturer: STMicroelectronics
• Type: High Quality front end videor

Specifications of STV2310D

• Maximum Operating Temperature: + 70 C
• Package / Case: TQFP-64
• Minimum Operating Temperature: 0 C
• Mounting Style: SMD/SMT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Functional Description
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4.10
4.10.1 General Description
For correct programming the following formula must be checked:
Zt x (Zout - Zin) = N x (Zout -1)
where Zin = ZOOMIN_FACT ; Zout = ZOOMOUT_FACT ; Zt = ZOOMIN_OFFSET ; N number of Y
pixels per line (720 in Normal Pixel mode, 640 or 768 in Square Pixel mode).
RGB Insertion
The RGB signals are captured by three 8-bit A/D converters and should be synchronous to the
selected CVBS or Y/C sources. The RGB signals are also adjusted in the analog domain by clamp
circuits used for sourcing and sinking charges on the front end capacitor.
A digital adjustable gain can be applied to the RGB data flow, in order to adapt to the CVBS
dynamic range.
The RGB signals are YCrCb formatted and mixed with the YCrCb signals from the main picture.
Soft mixing is driven by the FB signal. The rising and falling edges of the FB signal are measured
with subpixel accuracy to perform correct insertion. (For more information, refer to
Mixer on page
The RGB insertion block also provides a Cr Cb overload mechanism. This mechanism is used to
avoid clipping YCrCb signals (i.e when the input RGB signals are too large). The Cr Cb overload
mechanism measures the chroma signal during the video line in order to compute the correcting
scale factor.
R
G
B
●
●
●
The ZOOMIN_FACT bits determine the zoom-in factor at the left and right edges of the picture
The ZOOMOUT_FACT bits determine the zoom-out factor at the center of the picture
The ZOOMIN_OFFSET bits determine the border width where the zoom factor increases from
the zoom-in factor to the zoom-out factor, starting from the left edge (resp. the border width
finishing on the right edge where the zoom factor decreases from the zoom-out factor to the
zoom-in factor)
FB
Converter
24).
Interpolator
8-bit
A/D
Figure 17: RGB Capture and Mixing with Main Picture
6-bit
R Clamp
G Clamp
B Clamp
Conversion
Matrix
Cr
Cb
Y
Processing
Formatting
4:2:2
and
Main Picture
(YCrCb)
Mixer
Soft
Section 4.8: Soft
Y
Cr
Cb
STV2310