
1997 May 16
2
Philips Semiconductors
Preliminary specification
Chinese Character System Teletext
(CCST) decoder
SAA5700
FEATURES
Acquisition and display of the 625-line PAL CCST
Chinese standard for teletext, with Chinese and Latin
character sets
Supports multiple DRAM sizes: 256K
×
4 bits,
1M
×
4 bits, 4M
×
4 bits and 2
×
1M
×
4 bits with an
additional decoder/demultiplexer IC
Acquires and stores in background up to (typically)
400 pages with 1M
×
4 bits external DRAM
CCST Fastext, with capability of displaying Chinese
characters on Fastext prompt row
Meshing for reduced contrast video background in
subtitles and boxes
Full line and screen colour to all edges of screen
Supports 625-line 50/100 Hz display modes
Scan-locked and stand-alone sync modes; supports
video-locked sync modes with external PLL
Easy control via high level I
2
C-bus SAFARI commands
Sync mode switching and picture centring via I
2
C-bus
SAFARI commands
Supports external decryption unit for encrypted data.
GENERAL DESCRIPTION
The SAA5700 is a Chinese teletext decoder suitable for TV
and multimedia applications. It incorporates all the data
slicing, acquisition and display circuitry on-chip, as well as
the logic for memory management. An external DRAM is
used to store the currently displayed page and also the
precaptured teletext pages.
An external ROM is used to store the ideographic Chinese
character set. There is a high level software interface with
easy commands for the control of the decoder. Control is
achieved via the I
2
C-bus.
The device is available in a QFP64 package.
ORDERING INFORMATION
TYPE NUMBER
PACKAGE
NAME
DESCRIPTION
VERSION
SAA5700GP
QFP64
plastic quad flat package; 64 leads (lead length 1.95 mm);
body 14
×
20
×
2.8 mm
SOT319-2