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High-speed communication with FPD-Link TI Precision Labs - FPD-Link
Prepared by Vijaya Ceekala
Presented by Casey McCrea
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FPD-Link enables high-speed video transport
Camera ECU Head Unit
Central Information
Display
Rear Seat Entertainment Control Unit
DVD
LCD LCD
Instrument Cluster Display
Instrument Cluster ECU
Head-Up Controller
Head-Up Display
Front View Cameras
Display Interfaces Camera Interfaces
An example of high-speed serial FPD-Link
• Serialization reduces pin counts and connector requirements
• Adaptive Equalization and CDR techniques compensate for signal impairments
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De-serializer
Serializer
PLL
PCLK
P->S
Ref. clk
S->P
BC Rx
Par. data
BC Tx
CDR A-EQ
Display
Panel
/
Video
Processor
Par. data
PCLK
Processor
/
Imager/ISP
Clk_in
Vcc Vcc
Tx Rx
PLL in FPD-Link • PLL stands for Phase Locked Loop
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PFD Charge
Pump VCO
1/N
up
down
Reference
clock Output
clock Loop
Filter
Feedback
clock
Clock and Data Recovery circuit
D Q
Phase
Detector
Loop Filter
Voltage
Controller
Oscillator
PLL
Recovered/
Retimed Data
Incoming
Data
Sampler
Recovered
Clock
Control
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Eye diagram to study FPD-Link end-to-end jitter
• The size of the eye opening determines the quality of the signal
1 UI
Jitter limits performance
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Scope Results
Clock jitter is a critical requirement in High Speed Serial Link
Bathtub Curve Performance
Random jitter reduces the eye opening
10-12
10-15
BER
0 1.0 0.5 0.2 0.8
Minimize Random Jitter (RJ)
via clean clocks
Minimize Deterministic Jitter (DJ) via
Equalization
1UI = 1/ Data Rate
DJ DJ
RJ RJ ISI, DDJ, VCC
Noise
ISI, DDJ, VCC
Noise
Eye closing due to jitter
Eye Open
FPD-Link system jitter components
• 3 main system components: transmitter, channel & receiver jitter
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De-serializer
Serializer
PLL
PCLK
P->S
Ref. clk
S->P
BC Rx
Par. data
BC Tx
CDR A-EQ
Display
Panel
/
Video
Processor
Par. data
PCLK
Processor
/
Imager/ISP
Clk_in
Vdd Vdd
Channel:
PCB+Connector+cable
Transmitter Jitter Channel Jitter Receiver Jitter
Channel jitter due to PCB traces and cable
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• Signal conditioning – coping with the loss
• Equalizing the channel – compensating for insertion loss in a channel
RG-174 Cable Attenuation Measurements (S21)
-24
-18
-12
-6
0
1.E+05 1.E+06 1.E+07 1.E+08 1.E+09 1.E+10S
21
(d
B)
Frequency (Hz)
1m55m10m10+5m15m1m5+1m51m5+5+1m5
700 M 1.4G -1.35684 -1.96093 -3.29194 -4.78308 -6.52766 -9.46343-9.75449 -14.1672 -9.70192 -14.077 -2.64264 -3.96488 -5.93373 -8.77949
Channel Equalization
EQTX CDR
Channel
Data
Input
Re-
timed
Data
High-speed FPD-Link
serializer output After the channel Equalized output
Inverted channel characteristics
EQ characteristics
Quiz
1. What kind of jitter is introduced due to signal attenuation inside a cable?
a) Random Jitter
b) Deterministic jitter
c) Periodic jitter
2. What kind of method is used to compensate for random jitter introduced due to power supply
noise?
a) Adaptive Equalizer (AEQ)
b) Random jitter introduced due to power supply cannot be reduced
c) Some of the random jitter effects due to power supply noise can reduced by filtering the
data stream
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Thank you
To find more FPD-Link technical resources and search products, visit
ti.com/interface/fpd-link-serdes/products.html
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