Service Manual - Cenatel

High-l evel command language
FLOF ( Fastext), and TOP support
10 pages memory on chip (10kB)
4-1-5- Display OSD Features
3kB OSD RAM on chip
WST level 1.5 compliant
WST level 2 parallel attributes
32 for eground/background colours
programmable colour look-up table
1024 mask programmable characters
17 national languages
(Latin, Cyrillic and Greek caracter sets)
Character matrix 10x10
4-color mode for user font
4-1-6- Audio Features
Three mono inputs
Two mono outputs
Programmable channel select
Volume control for one mono channel
4-1-7- General Features
Submicron CMOS technology
L ow-power standby mode
Single 20.25 MHz crystal
64-pin PSDIP package
4-1-8- Data Capture
The Video Front End section takes in the analogue Composite Video and Blanking Signal (CVBS), and from this
extracts the required data, which is then decoded and stored in memory.
The extraction of the data is performed in the digital domain. The first stage is to select and convert the analogue
CVBS signal into a digital form. This is done using 8 bit ADC sampling at 20.25 Mhz.
The digital data services transmitted in the VBI are selected and acquired separately form the video part. This is done
by the use of an adaptive data slicer. The following data types can be extracted : 625 line World System Teletext
(WST), VPS, WSS. The data is acquired and decoded by the teletext decoder (TPU), then stored in an SRAM lnterface.
4-1-9- Data Capture Features
Video Signal Quality detector
Data Capture for 625 lin e WST
Data Capture fo r VPS data (PDC system A)
Data C apture for Wide Screen Signalling (WSS) bit decoding
Real-time capture and decoding fo r WST Teletext in Hardware, to enable optimised microprocessor throughput
10 page memory stored On-Chip
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