1993_Motorola_Linear_Interface_ICs_Vol_2.pdf

Introduction
The MC44011, a member of the MC44000 Chroma 4
family, is a composite video decoder which has been tailored
for applications involving multimedia, picture-in-picture, and
frame storage (although not limited to those applications).
The first stage of the MC44011 provides color difference
signals (R-Y, B-Y, and Y) from one of two (selectable)
composite video inputs, which are designed to receive PAL,
NTSC, and S-VHS (Y,C) signals. The second stage provides
either RGB or YUV outputs from the first stage's signals, or
from a separate (internally selectable) set of RGB inputs,
permitting an overlay function to be performed. Adjustments
can be made to saturation; hue; brightness; contrast;
brightness balance; contrast balance; U and V bias;
subcarrier phase; and color difference gain ratio.
The above mentioned video decoding sections provide
the necessary luma/delay function, as well as all necessary
filters for sound traps, luma/chroma separation, luma
peaking, and subcarrier rejection. External tank circuits and
luma delay lines are not needed. For PAL applications, the
MC44140 chroma delay line provides the necessary
line-by-line corrections to the color difference signals
required by that system.
The MC44011 provides a pixel clock to set the sampling
rate of external AID converters. This pixel clock, and other
horizontal frequency related output signals, are phase-locked
Camp.
Video 1
Camp.
Video 2
Switches shown with control bits = o.
MC44011
FUNCTIONAL DESCRIPTION
Figure 35. PAUNTSC/S-YHS Decoder Block Diagram
Crystal Select
IS7A-7)
to the incoming sync. The VCO's gain is adjustable for
optimum performance. The MC44011 also provides vertical
sync and field identification (Field 1, Field 2) outputs.
Selection of the various inputs, outputs, and functions, as
well as the adjustments, is done by means of a two-wire 12C
interface. The basic procedure requires the microprocessor
system to read the internal flags of the MC44011, and then
set the internal registers appropriately. This 12C interface
eliminates the need for manual controls (potentiometers) and
external switches. All of the external components for the
MC44011, except for the two crystals, are standard value
resistors and capacitors, and can be non-precision.
(The DACs mentioned in the following description are 6-bits wide.
The settings mentioned for them are given in decimal values of 00 to
63. These are not hex values.)
PAUNTSC/S-VHS Decoder
A block diagram of this decoder section is shown in
Figure 35. This section's function is to take the incoming
composite video (at Pins 1 or 3), separate it into luma and
chroma information, determine if the signal is PAL or NTSC
(for the flags), and then provide color difference and luma
signals at the outputs. If the input is S-VHS, the
luma/chroma separation is bypassed, but the other functions
are still in effect.
Saturation ($87-510)
Hue ($88-510)
Color Balance ($78-5/0)
Blanking
MOTOROLA LINEAR/INTERFACE ICs DEVICE DATA
9-205
3.617.2/28.6/4.4/
8.8/35.4 MHz
Notch
Ident
R-YOut
B-YOut