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XDSG Display Mode (channel grazing):
Network Name, Call Letters,
Program Name,
Program Length, Time In Show
XDSF Display Mode (full information):
XDSG Display Mode information plus:
Program Type (only basic types),
Program Description.
INTRODUCTION
THE MC144144 DECODER
The MC144144 is a stand alone integrated circuit, capable
of processing VBI data from both fields of the video when the
data conforms to the transmission format defined in the Tele-
vision Decoder Circuits Act of 1990 and in accordance with
the EIA–608.
The Line 21 data stream can consist of data from several
data channels multiplexed together. Field 1 has four data
channels, two Captions and two Text. Field 2 has five addi-
tional data channels, two Captions, two Text, and Extended
Data Services (XDS). The XDS data structure is defined in
EIA–608.
Control Port Data Display Modes
In addition to displaying data extracted from Line 21 of the
incoming video, the MC144144 can display information sup-
plied through its serial port. This is referred to as the on–
screen display (OSD) mode. This mode provides:
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OSD display can use all Video Data Display modes and
features.
In this document, the term “user” refers to the television or
VCR designer. The user may choose to make certain option-
al features selectable by the viewer. These features then be-
come viewer options.
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Additional graphics features available.
Double high and double wide characters available.
Information may be placed anywhere on the screen.
OSD display can be locked to an external V signal, if
desired, to provide an OSD display when no video is
present.
DATA TRANSMISSION FORMAT
The composite data signal contained within the active por-
tion of the VBI line consists of a seven–cycle sine–wave
clock run–in burst, a start bit, and 16 bits of data. These 16
bits consist of two 7–bit characters and control codes, with
odd parity, that conform to the FCC closed caption decoder
requirements and EIA–608. The clock rate is 0.5035 MHz
Character Set
The MC144144 has a new character set with extended
features. For example:
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New font with lowercase letters having descenders.
Optional display mode using drop shadow.
EIA–608 extended characters.
EIA–608 background and foreground attributes.
Special framing and graphics for OSD display.
Double high and double wide character display for OSD.
Fifteen scan lines per character row for OSD and TEXT.
which is 32 x F . The clock burst and data packet are 50 IRE
H
units peak–to–peak and are filtered to a “2T” response. Data
is sent with the least significant bit (bit b0) being sent first and
the most significant bit (bit b7, the parity bit) being sent last.
MC144144 FEATURE SUMMARY
The primary features of the MC144144 are briefly de-
scribed below.
Serial Communications Interface
Communications and control of the MC144144 are
through a serial control interface. Two serial control modes
are available with the MC144144 performing as a slave de-
vice. These modes are:
VBI Data Processing
The MC144144 extracts the data in Line 21 of the incom-
ing video. All data channels in both fields are handled. Spe-
cifically, the MC144144 can:
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A two–wire, I C interface.
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Process data from both fields of Line 21 simultaneously.
Display data from any data channel.
Output XDS data through the serial port while displaying
selected data.
A three–wire, serial peripheral interface (SPI).
Five pins are dedicated to the control port function and one
pin can be configured to provide an interrupt output. These
pins are designated as:
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Output XDS data raw or filtered.
XDSfilterparametersuserselectablefromalistofpre–pro-
grammed values.
SMS = Serial mode select.
SCK = Serial port clock for either serial mode.
2
SDA = Serial port data for I C mode and data In for
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NTSC or PAL operation selectable.
SPI mode.
2
SDO = Serial data out for SPI mode. Not used in I C
Video Data Display Modes
mode.
The data extracted from the incoming video may be dis-
played in different ways, according to the user selection and
the type of data. The display features available are:
2
SEN = SPI mode enable signal. Must be HIGH for I C
mode.
VIN/INTRO = INTRO mode = Interrupt output on
selected event (when used).
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Ten different data display modes, CC1–CC4, T1–T4, and
two XDS displays.
2
I C Mode
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Pop–on, Paint–on, and Roll–up CAPTION displays.
TEXT display default is a full–screen, 15–row display.
User able to vertically reduce and reposition the TEXT dis-
play as desired.
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I C mode is selected by bringing the SMS pin LOW and
SEN pin HIGH.
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Acts as a slave device.
SDA and SCK pins are the data and clock lines of this port.
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Color or Monochrome display mode selectable.
MC144144
7
MOTOROLA