SERVICE MANUAL FOR M35&36; CHASSIS

TCL
7. VCT3831A Video/Controller/Teletext IC
Chassis M35&36 Service Manual
Introduction
The VCT 3831A is a high-quality singlechip TV processors. Modular design and a submicron technology allow
the economic integration of features in all classes of TV sets. VCT 3831A contains the entire video, display
and deflection processing for 4:3 and 16:9 50/60-Hz TV sets. The integrated microcontroller is supported by a
powerful OSD generator with integrated teletext acquisition which can be upgraded with onchip page memory.
With volume control and audio input select the basic audio features for mono TV sets are integrated.
Features
1. Video Features
– four composite video inputs, two S-VHS inputs
– analog YCrCb input
– composite video monitor
– multistandard color decoder (1 crystal)
– multistandard sync decoder
– black-line detector
– adaptive 2H comb filter Y/C separator
– horizontal scaling (0.25 to 4)
– Panoramavision
– black-level expander
– dynamic peaking
– soft limiter (gamma correction)
– color transient improvement
– programmable RGB matrix
– analog RGB/Fastblank input
– half-contrast switch
– picture frame generator
– scan velocity modulation output
– high-performance H/V deflection
– angle and bow correction
– separate ADC for tube measurements
– EHT compensation
2. Microcontroller Features
– 8-bit, 10-MHz CPU (65C02)
– 96 kB program ROM on chip
– 1 kB program RAM on chip
– memory banking
– 16-input, 16-level interrupt controller
– patch modul for 10 ROM locations
– two 16-bit reloadable timers
– capture compare modul
– watchdog timer
– 14-bit PWM for voltage synthesis
– four 8-bit PWMs
– 10-bit ADC with 15:1 input MUX
– I2C bus master interface
– 24 programmable I/O ports
3. OSD Features
– 3 kB OSD RAM on chip
– WST level 1.5 compliant
– WST level 2 parallel attributes
– 32 foreground/background colors
– programmable color look-up table
– 1024 mask programmable characters
– 24 national languages
(Latin, Cyrillic, Greek, Arabic, Farsi, Hebrew)
– character matrix 8x8, 8x10, 8x13, 10x8, 10x10, 10x13
– vertical soft scroll
– 4-color mode for user font
4. Teletext Features
– four programmable video inputs
– acquisition is independent from display part
– adaptive data slicer
– signal quality detection
– WST, PDC, VPS, and WSS acquisition
– high-level command language
– EPG, FLOF, and TOP support
– 10 pages memory on chip
– up to 500 pages with external SRAM
5. Audio Features
– three mono inputs
– two mono outputs
– programmable channel select
– volume control for one mono channel
6. General Features
– submicron CMOS technology
– low-power standby mode
– single 20.25-MHz crystal
– 64-pin PSDIP package
– 128-pin PMQFP package
– emulator chip for software development
38 03.Mar.2003