GENERAL DESCRIPTION

The OM8373 and OM8378 combine the functions of a

video processor together with a m-Controller and US

Closed Caption decoder. The ICs are intended to be used

in economy television receivers with 110° picture tubes.

The ICs have supply voltages of 8 V and 3.3 V and they

are mounted in a SDIP-64 envelope.

The features are given in the following feature list.

FEATURES

TV-signal processor

· Vision IF circuit suitable for negative modulation with

alignment-free PLL demodulator

· Internal (switchable) time-constant for the IF-AGC circuit

· The mono intercarrier sound circuit has a selective

FM-PLL demodulator which can be switched to the

different FM sound frequencies (4.5/5.5/6.0/6.5 MHz).

The quality of this system is such that the external

band-pass filters can be omitted.

· Source selection between the ‘internal’ CVBS and an

external CVBS or Y/C signal

· 1 external audio input.

· Integrated chrominance trap circuit

· Integrated luminance delay line with adjustable delay

time

· Picture improvement features with peaking (with

switchable centre frequency, depeaking, variable

positive/negative overshoot ratio and video dependent

coring), dynamic skin tone control and blue- and black

stretching. All features are available for CVBS, Y/C and

YPBPR signals.

· Tint control for all internal and external signals

· Integrated chroma band-pass filter with switchable

centre frequency

· Only one reference (12 MHz) crystal required for the

m-Controller and the colour decoder

· NTSC or PAL/NTSC colour decoder with automatic

search system

· Internal base-band delay line

· Indication of the Signal-to-Noise ratio of the incoming

CVBS signal

· A linear RGB/YUV/YPBPR input with fast blanking for

external RGB/YUV sources. The synchronisation circuit

can be connected to the incoming Y signal. The OSD

signals are internally supplied from the m-Controller.

· RGB control circuit with ‘Continuous Cathode

Calibration’, white point and black level off-set

adjustment so that the colour temperature of the dark

and the light parts of the screen can be chosen

independently.

· 2 levels of contrast reduction of main picture possible

during OSD/Text insertion (‘halftone’)

· OSD/Text gain reduction control

· Adjustable ‘wide blanking’ of the RGB outputs

· Horizontal synchronization with two control loops and

alignment-free horizontal oscillator

· Vertical count-down circuit

· Vertical driver optimized for DC-coupled vertical output

stages

· Horizontal and vertical geometry processing

· Horizontal and vertical zoom function for 16 : 9

applications

· Horizontal parallelogram and bow correction for large

screen picture tubes

· Low-power start-up of the horizontal drive circuit

· Macrovision keying possibility for horizontal

synchronisation.

m-Controller

· 80C51 m-controller core standard instruction set and

timing

· 1 ms machine cycle

· 48Kx8 or 55Kx8-bit late programmed ROM.

· Character ROM size up to 9kx8-bit. The unused

character ROM size can be used as additional program

ROM.

· 3.5Kx8-bit Auxiliary RAM (up to 1.25KX8-bit required for

Display)

· Interrupt controller for individual enable/disable with two

level priority

· Two 16-bit Timer/Counter registers

· One 16-bit Timer with 8-bit Pre-scaler

· WatchDog timer

· Auxiliary RAM page pointer

· Standby, Idle and Power Down modes

· 14-bit PWM for Voltage Synthesis Tuning

· 4-bit A/D converter

· 4 pins which can be programmed as general I/O pin,

ADC input or PWM (6-bit) output