FFA-GMSL-SerDes#
On the FRAMOS Functional Adapters (FFAs) for GMSL, Maxim’s “Gigabit Multimedia Serial Link” is utilized to transfer up to 12 Gbps of uncompressed video data, I2C communication, GPIOs and Power via a single coax wire with automotive grade Fakra connectors.
Figure: Block Diagram of FFA-GMSL-Ser and FFA-GMSL-Des inside the FSM Ecosystem.
As shown in the figure, the integration takes place in form of a serializer- (FFA-GMSL-Ser) and deserializer- (FFA-GMSL-Des) board, that create the appropriate GMSL line between each other and providing PixelMate™ conform MIPI CSI-2 connectivity on in- / output to FSA / FPA. This way they are physically compatible to all FSMs of the Ecosystem with this interface.
Note: Due to high power requirements of specific sensors, even if physically interface compatible, operation might not be possible due to lack of power over coax. Please check the following table for an overview about tested and confirmed setups.
Driver Implemented Modes [Full Resolution / max. FPS] |
||||
|---|---|---|---|---|
Modules |
Physically Compatible |
Reference Drivers (NVIDIA Jetson) |
6 Gbps Driver support on request, physically supported. |
12 Gbps |
FSM-AR0144 |
Yes |
On Request |
||
FSM-AR0521 |
Yes |
On Request |
||
FSM-AR1335 |
Yes |
On Request |
||
FSM-HDP230 |
Yes |
On Request |
||
FSM-IMX264 |
Yes |
On Request |
||
FSM-IMX283 |
Yes |
On Request |
||
FSM-IMX290 |
Yes |
Yes |
1920 x 1080 / 120 |
|
FSM-IMX327 |
Yes |
On Request |
||
FSM-IMX296 |
Yes |
Yes |
1456 x 1088 / 60 |
|
FSM-IMX297 |
Yes |
On Request |
||
FSM-IMX304 |
Yes[1] |
Yes |
4112 x 3008 / 24 |
|
FSM-IMX334 |
Yes |
On Request |
||
FSM-IMX335 |
Yes |
On Request |
||
FSM-IMX412 |
Yes |
Yes |
4056 x 3040 / 60 |
|
FSM-IMX477 |
Yes |
On Request |
||
FSM-IMX577 |
Yes |
Yes |
4056 x 3040 / 60 |
|
FSM-IMX415, 715 |
Yes |
Yes |
3864 x 2192 / 90 |
|
FSM-IMX462 |
Yes |
Yes |
1920 x 1080 / 120 |
|
FSM-IMX662 |
Yes |
Yes |
1920 x 1080 / 98 |
|
FSM-IMX464 |
Yes |
Yes |
2712 x 1538 / 90 |
|
FSM-IMX485 |
Yes |
On Request |
||
FSM-IMX568 |
Yes |
Yes |
2472 x 2064 / 96 |
|
FSM-IMX585 |
Yes |
Yes |
3856 x 2180 / 90 |
|
FSM-IMX530 |
Yes[2] |
Yes |
5328 x 4608 / 15 |
|
FSM-IMX565 |
Yes |
Yes |
4128 x 3008 / 43 |
|
FSM-IMX675 |
Yes |
Yes |
2608 x 1964 / 81 |
|
FSM-IMX678 |
Yes |
Yes |
3856 x 2180 / 72 |
|
FSM-IMX990 |
Yes |
Yes |
1296 x 1032 / 125 |
Table: FRAMOS Sensor Module Compatibility and Support by FFA-GMSL-SerDes
Note: With the revision V1A of the FFA-GMSL-Des (Deserializer), only one GMSL line is supported per carrier board. The power supplied from the carriers is not sufficient to source multiple or demanding image sensors. The V2A variant supports more power demanding image sensors with an external 12V power supply.
Latency
The latency added by GMSL conversion is related to the data rate and image width. It is 1 video line + 128 x TPCLK where TPCLK is the pixel clock of the sensor. As the actual delay depends on the operation mode, you can find a few examples for orientation below.
Modules |
Resolution [V x H] |
Framerate [fps / Hz] |
Latency [µs] |
|---|---|---|---|
FSM-IMX462 |
1920 x 1080 |
60 120 |
7,76 8,26 |
FSM-IMX415 |
3864 x 2192 |
45 90 |
23,55 10,15 |
FSM-IMX283 |
5496 x 3694 |
12 25 |
47,21 31,58 |
The values needed for calculation can be found in the corresponding sensor datasheet.
Sensor Communication and General Purpose Input- / Outputs (GPIO)
The SerDes chain embeds several (sensor) signals as well as communication into the GMSL stream. It is differentiated between 10 available multi-functional pins (MFP), providing latency optimized signals, and slower signals available by an IO extender communicating via I2C:
GPIO Extender:
SLAMODE0, SLAMODE1, SLAMODE2, XMASTER, TOUT0, TOUT1, TOUT2
Multi-Functional Pins
MFP0: SCK
MFP1: XCE
MFP2: XCLR
MFP3: XVS
MFP4: INCK (MFP4 is output of PLL, can generate a 1-75 MHz clock)
MFP5: XHS (OD out)
MFP6: XTRIG1 (OD out)
MFP7: SDI or I2C SDA (configurable)
MFP8: SDO or I2C SCL (configurable)
MFP9: XTRIG2 (OD out)
MFP10: NC
For details on the specific signals, check the documentation of your image sensor and FSA type.
FFA-GMSL-Ser-V1A (Serializer, Sensor Side)#
Serializer board acting as transmitter (TX), connecting to FSM+FSA stack serializing image data, embedding of bidirectional communication and sensor GPIOs. Connects to PixelMateC and outputs GMSL on Fakra type connector.
4-Lane MIPI CSI-2 Input
Supporting 6 / 12 Gbps output modes
Generic supply voltage (3V8, 1V8) recovery from PoC
GPIOs and I2C Communication via MFP/ I2C Extender
Testpoints to important signals
Compatible to GMSL 6 / 12 Gbps compliant receivers.
Fakra / GMSL Connector |
PixelMateC™ Connector |
|
|
FFA-GMSL-Ser-V2A (Serializer, Sensor Side)#
Serializer board acting as transmitter (TX), connecting to FSM+FSA stack serializing image data, embedding of bidirectional communication and sensor GPIOs. Connects to PixelMateC and outputs GMSL on Fakra type connector.
4-Lane MIPI CSI-2 Input
Supporting 6 / 12 Gbps output modes
Generic supply voltage (3V8, 1V8) recovery from PoC
V2A: 26.5 mm footprint2
GPIOs and I2C Communication via MFP/ I2C Extender
Testpoints to important signals
Compatible to GMSL 6 / 12 Gbps compliant receivers.
Fakra / GMSL Connector |
PixelMateC™ Connector |
|
|
FFA-GMSL-Des-V1A (Deserializer, Processor Side)#
The deserializer board acts as a receiver (RX) by converting GMSL data (on the input) to FPA or Carrier boards using the PixelMateC interface. This board comes in two variants, namely FFA-GMSL-Des-V1A and FFS-GMSL-Des-V2A, both of which are responsible for deserializing image data, embedding bidirectional communication, and sensor GPIOs. They connect to the PixelMateC interface and output GMSL through a Fakra-type connector. The key features of the deserializer board are listed below, along with the differences between the V1A and V2A variants.
Supporting 6 / 12 Gbps input modes
4-Lane MIPI CSI-2 Output
Maximum one GMSL chain supported per FPA/Carrier
Testpoints to important signals
Power over Coax (PoC) Injection
Fakra / GMSL Connector |
PixelMateC™ Connector |
|
|
FFA-GMSL-Des-V2A (Deserializer, Processor Side)#
The deserializer board acts as a receiver (RX) by converting GMSL data (on the input) to FPA or Carrier boards using the PixelMateC interface. This board comes in two variants, namely FFA-GMSL-Des-V1A and FFS-GMSL-Des-V2A, both of which are responsible for deserializing image data, embedding bidirectional communication, and sensor GPIOs. They connect to the PixelMateC interface and output GMSL through a Fakra-type connector. The key features of the deserializer board are listed below, along with the differences between the V1A and V2A variants.
Supporting 6 / 12 Gbps input modes
4-Lane MIPI CSI-2 Output
Power over Coax (PoC) Injection
V2A variant allows a separate, carrier independent power input
Testpoints to important signals
Supports multi-sensor operation on the FPA/Carrier
Fakra / GMSL Connector |
PixelMateC™ Connector |
|
|
Pinout: J1 (PixelMateC)
Pin # |
Name |
Pin # |
Name |
|---|---|---|---|
1 |
3V8_VDD |
2 |
1V8_VDD |
3 |
3V8_VDD |
4 |
1V8_VDD |
5 |
NC |
6 |
NC |
7 |
NC |
8 |
NC |
9 |
NC |
10 |
NC |
11 |
GND |
12 |
GND |
13 |
GND |
14 |
GND |
15 |
RST_0 |
16 |
RST_1 |
17 |
NC |
18 |
NC |
19 |
NC |
20 |
NC |
21 |
I2C_0_SCL(SPI_SCK) |
22 |
NC |
23 |
NC |
24 |
NC |
25 |
GPIO1(XVS0) |
26 |
NC |
27 |
I2C_0_SDA(SPI_MOSI) |
28 |
NC |
29 |
GPIO2(XHS0) |
30 |
GPIO10(XTRIG1) |
31 |
GPIO3(XTRIG0) |
32 |
NC |
33 |
PW_EN_0 |
34 |
PW_EN_1 |
35 |
NC |
36 |
NC |
37 |
GND |
38 |
GND |
39 |
MCLK_0 |
40 |
NC |
41 |
NC |
42 |
NC |
43 |
GND |
44 |
GND |
45 |
NC |
46 |
D_DATA_3_P |
47 |
NC |
48 |
D_DATA_3_N |
49 |
GND |
50 |
GND |
51 |
D_DATA_0_N |
52 |
D_DATA_1_N |
53 |
D_DATA_0_P |
54 |
D_DATA_1_P |
55 |
GND |
56 |
GND |
57 |
D_DATA_2_P |
58 |
D_CLK_0_P |
59 |
D_DATA_2_N |
60 |
D_CLK_0_N |
Table: Pinout of FFA-GMSL-Des-VXA, connector to FRAMOS Processor Adapter (FPA)
Device Details:
The FFA-GMSL-Des-V2A deserializer is similar to the V1A variant. However, it moves the PoC power source to an external power supply, making it independent of power limitations imposed by the FPA or carrier board. As a result, it can support demanding sensors as well as multi-sensor operation on the FPA/Carrier, whereas the V1A variant only supports one sensor. One GMSL deserializer physically supports 6 or 12 Gbps GMSL input, and one MIPI CSI-2 output via PixelMate™. The V2A deserializer receives power from a required external 12V power supply before being converted down by a switching buck converter to 8V, which is then available through Power over Coax (PoC):
Note: To provide power to the V2A deserializer, an external 12 V power supply is required. A power rating of 12 VDC, 1 A is recommended.
It is important to note that though 6 Gbps is physically supported in the V2A variant of the deserializer, NVIDIA Jetpack JP5.1 only supports the 12 Gbps speed.