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