SAA7102 Просмотр технического описания (PDF) - Philips Electronics

Номер в каталоге

Компоненты Описание

производитель

SAA7102

Digital video encoder

Philips Electronics 

Philips Semiconductors

Digital video encoder

Product specification

SAA7102; SAA7103

7 FUNCTIONAL DESCRIPTION

The digital video encoder encodes digital luminance and

colour difference signals (CB-Y-CR) or digital RGB signals

into analog CVBS, S-video and, optionally, RGB or

CR-Y-CB signals. NTSC M, PAL B/G and sub-standards

are supported.

The SAA7102; SAA7103 can be directly connected to a

PC video graphics controller with a maximum resolution of

800 × 600 at a 50 or 60 Hz frame rate. A programmable

scaler scales the computer graphics picture so that it will fit

into a standard TV screen with an adjustable underscan

area. Non-interlaced-to-interlaced conversion is optimized

with an adjustable anti-flicker filter for a flicker-free display

at a very high sharpness.

Besides the most common 16-bit 4 : 2 : 2 CB-Y-CR input

format (using 8 pins with double edge clocking), other

CB-Y-CR and RGB formats are also supported; see

Tables 25 to 29.

A complete 3 × 256 bytes Look-Up Table (LUT), which can

be used, for example, as a separate gamma corrector, is

located in the RGB domain; it can be loaded either through

the video input port PD (Pixel Data) or via the I2C-bus.

The SAA7102; SAA7103 supports a 32 × 32 × 2-bit

hardware cursor, the pattern of which can also be loaded

through the video input port or via the I2C-bus.

It is also possible to encode interlaced 4 : 2 : 2 video

signals such as PC-DVD; for that the anti-flicker filter, and

in most cases the scaler, will simply be bypassed.

Besides the applications for video output, the SAA7102;

SAA7103 can also be used for generating a kind of

auxiliary VGA output, when the RGB non-interlaced input

signal is fed to the DACs. This may be of interest for

example, when the graphics controller provides a second

graphics window at its video output port.

The basic encoder function consists of subcarrier

generation, colour modulation and insertion of

synchronization signals at a crystal-stable clock rate of

13.5 MHz (independent of the actual pixel clock used at

the input side), corresponding to an internal 4 : 2 : 2

bandwidth in the luminance/colour difference domain.

Luminance and chrominance signals are filtered in

accordance with the standard requirements of “RS-170-A”

and “ITU-R BT.470-3”.

For ease of analog post filtering the signals are twice

oversampled to 27 MHz before digital-to-analog

conversion.

The total filter transfer characteristics (scaler and

anti-flicker filter are not taken into account) are illustrated

in Figs 4 to 8. All three DACs are realized with full 10-bit

resolution. The CR-Y-CB to RGB dematrix can be

bypassed (optionally) in order to provide the upsampled

CR-Y-CB input signals.

The 8-bit multiplexed CB-Y-CR formats are “ITU-R BT.656”

(D1 format) compatible, but the SAV and EAV codes can

be decoded optionally, when the device is operated in

slave mode. For assignment of the input data to the rising

or falling clock edge see Tables 25 to 29.

In order to display interlaced RGB signals through a

euro-connector TV set, a separate digital composite sync

signal (pin 26) can be generated; it can be advanced up to

31 periods of the 27 MHz crystal clock in order to be

adapted to the RGB processing of a TV set.

The SAA7102; SAA7103 synthesizes all necessary

internal signals, colour subcarrier frequency and

synchronization signals from that clock.

Wide screen signalling data can be loaded via the I2C-bus

and is inserted into line 23 for standards using a 50 Hz

field rate.

VPS data for program dependent automatic start and stop

of such featured VCRs is loadable via the I2C-bus.

The IC also contains Closed Caption and extended data

services encoding (line 21), and supports teletext insertion

for the appropriate bit stream format at a 27 MHz clock rate

(see Fig.14). It is also possible to load data for the copy

generation management system into line 20 of every field

(525/60 line counting).

A number of possibilities are provided for setting different

video parameters such as:

• Black and blanking level control

• Colour subcarrier frequency

• Variable burst amplitude etc.

2001 Sep 25

10

Share Link: