STV2310D STMicroelectronics, STV2310D Datasheet - Page 25

• 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

STV2310
4.9
4.9.1
4.9.1.1 Square Pixel Mode
When one of the Alpha Blending modes is used for mixing, the alpha value is set in the
MIX_SLOPE[7:0] bits.
When the STV2310 is in normal RGB and CVBS mixing mode, the MIX_SLOPE[3:0] bits indicate
the mixing slope (duration of mixing). The MIX_SLOPE[7:4] bits must be set to 0000. The
MIX_SLOPE[3:0] bits code the soft mixing slope from 0000 to 1111, with 0000 corresponding to a
slope of 1 clock cycle (virtual 4 x f
signal to the other spanned on 16 clock cycles.
Output Scaler and Format Converter
General Description
An Output Sample Rate Converter (OSRC) is used to transpose the subcarrier locked virtual clock
domain to the output sample rate domain. This converter is used to provide a fixed number of pixels
per active line (i.e. 720 for ITU-R BT.601 format) independently of the input video standard and line
length.
The Output Sample Rate Converter compensates for line length variations. At this level, a skew
correction is applied on each pixel in order to compensate for the shift of the asynchronous
acquisition with respect to the current line horizontal sync pulse. New sample rate and skew
correction factors are computed at every line, taking into account the line length variation.
The Output Sample Rate Converter is also used to perform an horizontal format conversion to
support zoom in/out functions. For linear scaling, the scaling factor can be programmed in linear
steps from 0.25 to 4. Non-linear scaling is also available for Panorama mode. Region borders are
fully programmable as well as the associated scaling factors (in the 0.25 to 4 range).
At the sample rate converter output, an active line is transposed into a fixed number of skew
corrected pixels, according to the selected output format (ITU-R BT.601 or square pixel). This is
used for the orthogonal display or field storage for the field-rate up-conversion, using an external up-
converter.
When a standard TV screen is used to display computer-generated images, Square Pixel mode is
required to ensure the correct aspect ratio in relation to the required sampling frequency of the TV
display format.
●
●
Upsampling is required for zoom-in functions.
Downsampling is required for zoom-out functions.
13.5 MHz
12.27 MHz
14.75 MHz
Luma Sampling Frequency
SC
Table 10: TV Display Formats
clock domain) and 1111 corresponding to a transition from one
ITU-R BT.601 (NTSC/PAL)
NTSC Square Pixel
PAL Square Pixel
Format
Functional Description
640
768
720
Pixels/Line
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