Panasonic Image Sensor Bridge
March 2012
Reference Design RD1121
Introduction
As image sensor resolutions have increased, Panasonic has chosen a differential high-speed serial interface
instead of using a traditional CMOS parallel interface for their sensors. This was done because the resolution and
frame rate of the MN34041 and MN34081 are sizable. An interface of higher bandwidth and lower noise than a
standard CMOS parallel bus was required. The Panasonic MN34041 and the MN34081 are image sensors that
output 2.1M pixels and 1.33M pixels, respectively. The MN34041 outputs two serial data streams up to three lanes
wide. The MN34081 outputs two serial data streams up to two lanes wide. Each stream has its own clock.
The Panasonic Image Sensor Bridge reference design is configured to utilize the two data streams with two lanes.
The full resolution of the Panasonic sensor is supported (MN34041: 1944x1092 at 60 fps, MN34081: 1304x1024 at
60 fps). The design output is a 12-bit parallel data bus that a standard Image Signal Processor (ISP) can read
(Figure 1).
Figure 1. Panasonic Image Sensor Bridge Block Diagram
Panasonic
Area Sensor
Serial-to-Parallel
Conversion
Multi-Link
Alignment
Active Video
Extraction
Parallel
Data to ISP
Each input port is a sub-LVDS signal and can operate up to 500 Mbps. The output signals interfacing to the ISP are
single-ended LVCMOS pins and can be driven at 1.8V, 2.5V and 3.3V. For technical details regarding the image
sensor, please contact Panasonic.
Complete Reference Design for Panasonic to Parallel Sensor Bridge
The complete reference design includes a sensor bridge NGO and HDL wrappers for component primitives specific
to the targeted device family. Reference design blocks diagram are shown in Figures 2 and 3.
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rd1121_01.4
Panasonic Image Sensor Bridge
Figure 2. Reference Design Top Level Block Diagram
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Panasonic Image Sensor Bridge
Figure 3. Reference Design NGO Wrapper Block Diagram
Table 1. Sensor Bridge NGO Port Definitions
Signal
Definition
Direction
reset_n
Reset, active low
Input
serial_clk_1
Serial link channel 1 clock
Input
serial_clk_2
Serial link channel 2 clock
Input
serial_data[3:0]
Serial link data:
serial_data [0], ch1 port 0
serial_data [1], ch1 port 1
serial_data [2], ch2 port 0
serial_data [3], ch2 port 1
Input
start
Indicating pixel clock is available
Output
parallel_clk
(serial_clk/2 * 4/3)
Output
parallel_data[11:0]
12-bit parallel data
Output
parallel_lv
Indicates active video data inside a line
Output
parallel_fv
Indicates active lines
Output
Panasonic Sensor Bridge NGO File
The Panasonic Sensor Bridge NGO accepts the deserialized data lanes and formats them to a 12-bit parallel bus
(Figure 4). First, the data on each lane is word-aligned to 12 bits. Second, the lanes are aligned to each other.
Finally, the word- and lane-aligned data is parsed into the parallel bayer output.
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Panasonic Image Sensor Bridge
Figure 4. Sensor Bridge NGO Block Diagram
Table 2. Sensor Bridge NGO Port Definitions
Signal
Definition
Direction
rstn
Reset, active low
Input
clk_162
Active Video Extraction Clock:
(4/3 * clk_div2); clock speed can vary
depending on sensor oscillator and sensor
PLL configuration.
Input
clk_148_5
Reserved; tie to 1’b0.
Input
data_lane[15:0]
Deserialized data:
data_lane[3:0], ch1 port 0
data_lane[7:4], ch1 port 1
data_lane[11:8], ch2 port 0
data_lane[15:12], ch2 port 1
Input
f_valid_o
frame valid, active high
Output
l_valid_o
line_valid, active high
Output
dout_o[11:0]
Parallel data Dout_o[11:0]
Output
clk_div2
Output clock, Serial clock/2
Output
The simulation screen shot in Figure 5 shows the time of the serial lane inputs to the output of the Multi-Link Alignment Module. Note that the dout bit order is reversed in the simulation. Also, channel 1 and channel 2 use the
same serial link clock, sclk_i. This is to simplify the test bench source code. In the actual design, the two clock signals are utilized to capture the deserialize data from each port. A FIFO on each lane is used to create a common
clock domain.
Figure 5. Sensor Bridge Simulation
In the simulation dout_o = {ch2 port1, ch2 port0, ch1 port1, ch1 port0}, each chx portx is 12-bit parallel pixel data.
The 12-bit parallel bus output is muxed from this and synced to f_valid_o and l_valid_o.
Figures 6 and 7 show the simulation for this reference design. Figure 6 shows an entire frame being transmitted,
while Figure 7 shows the start of a frame.
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Panasonic Image Sensor Bridge
Figure 6. Reference Design Simulation (Full Frame)
Figure 7. Reference Design Simulation (At Start of Frame)
The following is a summary of this reference design:
1.
A 2-channel, 2-port sensor bridge NGO is instantiated to implement the serial-to-parallel conversion.
2.
Clock domain transfer to parallel_clk.
3.
The final parallel output is 12-bit pixel words at a clock rate of serial_clk/2 *4/3 in Bayer format.
4.
Line valid and frame valid signals are generated to indicate active pixels in a line and active lines in a
frame.
Table 3. Sensor Bridge Resource Utilization in a LatticeXP2 and MachXO2 Devices
Complete Sensor Bridge
Reference Design
Registers
Slices
LUTs
EBRs
LatticeXP2
596
468
443
0
MachXO2
822
648
517
0
Table 4. Place & Route Timing Analysis (Based on LatticeXP2-5E and MachXO2-1200HC Devices in
132-Ball csBGA Packages)
LatticeXP2
MachXO2
-5
-6
-7
-4
-5
-6
Units
clk_div2 (Max.)
150.852
176.243
189.861
138.485
143.802
164.231
MHz
parallel_clk (Max.)
193.386
213.493
262.674
164.096
181.554
208.464
MHz
1. MN34041 maximum internal operating frequency = 500 MHz (Table 1.2.6 of MN34041 data sheet). Normal operating frequency is
486 MHz. This means the maximum nominal serial clock speeds are 243 MHz respectively.
2. clk_div2 (Max) = serial_clk/2 = 250MHz/2 = 125MHz. clk_div2(nominal) = 121.5 MHz. Please consider sensor operating speeds
when choosing device speed grades. parallel_clk (max) = 4/3 * clk_div2 = 166.67MHz. parallel_clk (nominal) = 162 MHz. Please
consider sensor operating speeds when choosing device speed grades.
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Panasonic Image Sensor Bridge
Table 5. Pinout for Complete Sensor Bridge in a LatticeXP2-5 or MachXO2-1200 Device
LatticeXP2-5
132-Ball csBGA
MachXO2-12001
132-Ball csBGA
SDOCAP
H1
N6
SDOCAN
H3
P6
SDOCBP
L1
M7
Bridge Signal Name
SDOCBN
L3
N8
SDODAP_0
D2
M11
SDODAN_0
E3
P12
SDODAP_1
D1
P8
SDODAN_1
E1
M8
SDODBP_0
F3
M9
SDODBN_0
G2
N10
SDODBP_1
C2
N3
SDODBN_1
D3
P4
RESET_TO_SENSOR
B9
F2
PSV
C9
C3
MSSEL
A7
D1
RESET_BAR
F12
C1
PIXCLK
P2
A11
FRAME_VALID
P14
B7
LINE_VALID
P13
C4
DOUT0
N8
C6
DOUT1
M6
B3
DOUT2
M5
C11
DOUT3
M7
A12
DOUT4
N12
A7
DOUT5
N7
B5
DOUT6
P12
A9
DOUT7
P5
A10
DOUT8
P6
A2
DOUT9
N2
B12
DOUT10
P7
C12
DOUT11
N4
B13
TCK
K14
B6
TDI2
L13
B4
2
TDO
K13
A4
TMS2
L12
A6
2
1. When using the pins in this table for the MachXO2-1200 device, termination resistors
are built in for serial_data SDOD lines and serial_clk SDOC lines.
2. All parallel data signals reside on Bank 0 for the MachXO2 and Banks 4 and 5 for the
LatticeXP2. Voltage rails for these banks should be considered when interfacing directly
to an ISP.
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Panasonic Image Sensor Bridge
Tested Designs
The Panasonic Image Sensor Bridge has been tested with the Texas Instruments IPNC DM812X and DM385. See
Leopard Imaging at www.leopardimaging.com for details on the Texas Instruments IP camera design.
References
• Target Specifications – Area Sensor MN34041PL, Panasonic Corporation
• Target Specifications – Area Sensor MN34081PLJ, Panasonic Corporation
Technical Support Assistance
Hotline: 1-800-LATTICE (North America)
+1-503-268-8001 (Outside North America)
e-mail: [email protected]
Internet: www.latticesemi.com
Revision History
Date
Version
May 2011
01.0
Change Summary
Initial release.
February 2012
01.1
Added data on MN34081 and the MachXO2 pinout.
March 2012
01.2
Document updated with new corporate logo.
Place & Route Timing Analysis table – Corrected speed grade information for MachXO2.
Added first footnote to the Pinout table.
March 2012
01.3
Updated Pinout table.
March 2012
01.4
Updated Pinout table footnote.
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