SAA7128H/V1,557 NXP Semiconductors, SAA7128H/V1,557 Datasheet - Page 10

• Manufacturer Part Number: SAA7128H/V1,557
• Manufacturer: NXP Semiconductors

Specifications of SAA7128H/V1,557

• Adc/dac Resolution: 10b
• Screening Level: Commercial
• Package Type: PQFP
• Pin Count: 44
• Lead Free Status / RoHS Status: Compliant

Philips Semiconductors
9397 750 14325
Product data sheet
7.3.1 Video path
7.3.2 Teletext insertion and encoding
7.2 Data manager
7.3 Encoder
In the data manager, a pre-defined color look-up table located in this block can be read
out in a pre-defined sequence (8 steps per active video line) as an alternative to the
external video data, achieving a color bar test pattern generator without the need for an
external data source.
The encoder generates out of Y, U and V baseband signals luminance and color
subcarrier output signals, suitable for use as CVBS or separate Y and C signals.
Luminance is modified in gain and in offset (latter programmable in a certain range to
enable different black level set-ups). A blanking level can be set after insertion of a fixed
synchronization pulse tip level in accordance with standard composite synchronization
schemes. Other manipulations used for the Macrovision anti-taping process such as
additional insertion of AGC super-white pulses (programmable in height) are supported by
the SAA7128H only.
In order to enable easy post analog filtering, luminance is interpolated from a 13.5 MHz
data rate to a 27 MHz data rate, providing luminance in 10-bit resolution. The transfer
characteristics of the luminance interpolation filter are illustrated in
Figure 10
synchronization pulses are ensured.
Chrominance is modified in gain (programmable separately for U and V), standard
dependent burst is inserted, before baseband color signals are interpolated from a
6.75 MHz data rate to a 27 MHz data rate. One of the interpolation stages can be
bypassed, thus providing a higher color bandwidth, which can be made use of for Y and C
output. The transfer characteristics of the chrominance interpolation filter are illustrated in
Figure 8
The amplitude, beginning and ending of the inserted burst, is programmable in a certain
range that is suitable for standard signals and for special effects. Behind the succeeding
quadrature modulator, color in a 10-bit resolution is provided on the subcarrier.
The numeric ratio between Y and C outputs is in accordance with the respective
standards.
Pin TTX receives a WST or NABTS teletext bitstream sampled at the LLC clock. Two
protocols are provided:
Phase variant interpolation is achieved on this bitstream in the internal teletext encoder,
providing sufficient small phase jitter on the output text lines.
•
•
At each rising edge of output signal (TTXRQ) a single teletext bit has to be provided
after a programmable delay at input pin TTX
The signal TTXRQ performs only a single LOW-to-HIGH transition and remains at
HIGH-level for 360, 296 or 288 teletext bits, depending on the chosen standard.
and
and
Figure
Figure
9.
Rev. 03 — 9 December 2004
11. Appropriate transients at start/end of active video and for
SAA7128H; SAA7129H
© Koninklijke Philips Electronics N.V. 2004. All rights reserved.
Digital video encoder
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