Automotive AV Interface Transmits Full-Color Video and
Supports Copyright Protection over a Single Differential Pair Cable
CXM4017R
CXM4018R
The convergence of consumer and automotive technologies is
accelerating, with the amount of digital electronic content increasing exponentially. High quality digital and audio is no longer restricted to the home. The car is transforming into a digital living
space, with access to the technologies people enjoy. Delivery of
DVD and other digital TV video brings the issue of content protection/digital rights management. To meet this need, Sony has
added HDCP*1 copyright protection to Gigabit Video Interface
(GVIF) technology. Next generation automotive entertainment
systems are now able to deliver copy-protected 24-bit color digital video over a single differential pair cable.
■
Support for 24-bit full-color QVGA, VGA,
WVGA, SVGA, and XGA display formats
■
Includes copyright protection technology
(HDCP) and built-in GVIF-HDCP keys (DVDCCA*2 approved)
■
Transmitter (CXM4017R): built-in PLL synthesizer and differential cable driver circuits
■
Receiver (CXM4018R): built-in clock and
data recovery PLL and adaptive cable
equalizer circuits
■
CMOS logic interface
■
Dual 2.5 V/3.3 V power supplies, low power
consumption
The continually evolving GVIF supports automotive entertainment.
■
LQFP 100-pin packages
■
Allows existing GVIF cables to be used
without change
*1 HDCP: High Bandwidth Digital Content Protection
*: See the following web page for more detailed information.
http://www.sony.net/Products/SC-HP/application/gvif/index.html
The CXM4017R and CXM4018R comprise an HDCP compliant chipset for serial transmission of 24-bit full-color digital video in the QVGA, VGA, WVGA,
SVGA, and XGA formats. Figure 1 shows
the block diagrams of the CXM4017R and
CXM4018R. The CXM4017R is a transmitter IC that includes encoder, parallelto-serial converter, and cable driver functions. The CXM4018R is a receiver IC
that includes cable equalizer, serial-to-
V
O
I
C
Japan will switch over completely
to digital for terrestrial broadcasting in 2011. And the Blu-ray Disc
is rapidly gaining popularity. Now
that technologies that transmit
high-definition video data without
degradation directly in its digital
form are desired, GVIF is the only
technology that can transmit 2
Gbps serial signals over just a
single differential pair cable and
furthermore provides copyright
protection functions. I believe that
in the near future GVIF will be deployed in all car models to make
car life an even more fulfilling experience.
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E
*2 DVD-CCA: DVD Copy Control Association
parallel converter, and decoder functions.
The CXM4017R and CXM4018R ICs include embedded HDCP-Cipher technology
and HDCP keys required to support HDCP
copyright protected transmission. Using
HDCP technology, GVIF is uniquely
suited for use in automotive entertainment
systems based on emerging and increasingly popular digital formats, including
DVD and digital TV. Figures 2 and 3 show
application and connection examples for
the CXM4017R and CXM4018R.
Features of GVIF
Transmission
GVIF combines 24-bit video display data,
a 2-bit sync data (HSYNC/VSYNC), 2-bit
control data (DE/AUX) and authentication
data. This serialized data is all delivered
over a low amplitude differential signal at
speeds of 240 to 1950 Mbps. This can all
be achieved using a single shielded twisted
pair (STP) cable with 100 Ω impendence.
The unique GVIF coding provides DC
balance which allows transmitted data
stably. Multiple panel resolutions are supported using the automatic frequency negotiation feature (SFTCLK: 8 to 65 MHz).
Authentication Over the
Same Differential Pair Cable
In copyright protected transmission, a signal encrypted by the transmission IC is
decrypted by the reception IC. To maintain the integrity of the protection, the
transmitting master device must determine
(authenticate) whether or not the receiving slave device is appropriate to receive
the data. This digital handshake is
achieved by utilizing a unique Sony technology to superpose an authentication signal of up to 400 Kbps from the receiver
IC to the transmitter IC over a single differential pair cable. Existing GVIF cables
can be used as is with no modification.
Built-in Cable Driver and
Cable Equalizer Circuits
The CXM4017R includes a low-voltage
differential signal cable driver circuit and
the CXM4018R includes an adaptive cable
equalizer circuit. Since the cable equalizer
automatically compensates the cable attenuation characteristics, the application
designers can freely select any cable length
up to 10 meters.
Figure 4 shows the serial data eye pattern
before and after the CXM4018R cable
equalizer circuit.
CXM4017R
RGB
H/Vsync
DE, AUX
HDCP
encoder
Parallel
to
serial
converter
GVIF
encoder
Cable
driver
GVIF output
SFTCLK
Microcontroller
EEPROM
STP cable
Up to 10 m
SDA/SCL
GPIO
System clock input
CXM4018R
RGB
Serial
to
parallel
converter
GVIF input
GVIF
decoder
H/Vsync
DE, AUX
HDCP
decoder
Cable
equalizer
SFTCLK
SDA/SCL
GPIO
System clock input
EEPROM
Microcontroller
■ Figure 1 Block Diagram
DVD player
Car navigation
unit
GVIF
Tx
Rx
DVD
Tx
HDCP-GVIF
Tx
Rx
Front seat
display
Rx
Rear seat
display
HDCP-GVIF
Front seat display
Rear seat display
Acquisition is stopped.
20.0 GSa/s 30.0 kpts
On
Tx CXM4017R
Rx GVIF receiver
(HDCP not supported)
Rx CXM4018R
■ Figure 3 Connection Example
■ Figure 2 Application Example
1
Tx GVIF transmitter
(HDCP not supported)
Acquisition is stopped.
20.0 GSa/s 30.0 kpts
200 mV/
2
On
3
On
1.00 V/
4
On
1
T
1
1/
On
200 mV/
2
On
3
On
1.00 V/
4
On
T
1
1/
3
H
More
(1 of 2)
Measurements
Color Grade
202 ps/
0.0 s
0
T
3
H
40 mV
More
(1 of 2)
Scales
Measurements
Color Grade
202 ps/
0.0 s
0
T
40 mV
Scales
?
Delete
All
1 17
18 35
36 70
71 141
142 282
283 564
565 1128
?
Delete
All
1 44
Serial data before equalization (Rx input pin)
45 89
90 179
180 358
359 716
717 1433
1434 2866
Serial data after equalization
Transmitted serial data rate: 1 Gbps
GVIF cable (STP):
30 m
■ Figure 4 Serial Data Eye Pattern Before and After the CXM4018R Cable Equalizer
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