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High-Speed Differential Pair Digital
Interface Technology:
"GVIF" (Gigabit Video Interface)
GVIF Technology for Automotive Applications |
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High-definition digital transmission |
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Differential pair digital interface |
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Thin, light, and long cables |
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High noise resistance, low electromagnetic
interference |
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Includes copyright protection functions |
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ARIB standard compliance |
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* "GVIF" is a trademark of Sony
Corporation.
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 The Shift to Digital in Image Transmission |
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In the LCD display market, where screen
sizes continue to grow and wide-screen has
become the mainstream, digital interfaces
have come to be widely used to connect
Blu-ray and DVD players to the display.
Compared to analog, digital interfaces
show almost no color mixing or resolution
degradation and can transmit images with
high definition. (See figure 2.)
At the same time, there are growing
demands for higher resolution in map display
and the ability to enjoy high-definition video
on the monitors used with in-car navigation
systems, and the switchover to digital is
progressing rapidly.
Furthermore, the places where digital
interfaces can play a role are expanding
to include not only the navigation monitor,
but the rear seat entertainment monitor
that allows passengers in the back to enjoy
movies and back and side monitors used to
improve safety. (See figures 1 and 3.)
Gigabit Video Interface (GVIF) is a unique Sony technology that takes advantage
of the features of the differential pair
digital transmission format to provide an
environment in which high-definition images
can be transmitted over a thin, light, and
long cable.
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| Differential Pair Digital Interface |
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GVIF is an interface standard developed
by Sony to transmit image signals from
sources such as a car navigation system
main unit or a DVD/Blu-ray player to a flat
panel display. (See figures 4 and 5.) GVIF
transmits uncompressed serial data at
speeds up to 1.95 Gbps. Unlike many other
digital interfaces that use multiple differential
pairs in their cable, GVIF transmits over
a single differential pair. As a result, the
cable is thin (under a 4 mm diameter) as
shown in figure 6, and since there are only a
small number of connections, the connector
size and mounting area can be compact
as well.
In automotive applications, where space
is particularly limited and it is desired to
reduce the total weight, these features
are significant advantages. Since a single
differential pair cable is used, there is no
skew between the differential pair signals,
and constraints on the reception circuit are
minimized.
At the same time, the speed of transmission
needs to be increased, and issues such
as long distance transmission and
electromagnetic interference must be
addressed as well. These issues are
controlled in a balanced and high-level
manner by the GVIF ICs. Transmission
distances up to ten meters are possible. At
the same time as transmitting 24-bit color
data with EGA, VGA, WVGA, SVGA, Dual
VGA, or XGA resolution, GVIF also supports
HDCP (High-Bandwidth Digital Content Protection System) content protection
technology. By using a GVIF transmission
IC that encodes the content together with a
GVIF reception IC that decodes the content,
digital video data with copyright protection
can be transmitted over a single differential
pair cable.
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Figure 1 : Automotive Entertainment and Interfaces
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 Multiplexing and Coding |
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See
all articles with figures and tables.  |
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Vol.62 |
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