Automotive Gateways Bridge & Gateway from Flexray/CAN/LIN to AVB Networks
Automotive Gateways Bridge & Gateway from FlexRay/CAN/LIN to AVB Networks
1 Content
Gateways in current/future architectures
Main GW functions (Routing, Diagnostic, …)
Main principles of GW’s functionality (SW aspects, protocol aspects, AUTOSAR aspects)
LIN/CAN/FlexRay 2 Ethernet transport mechanisms (1722a)
GW performance aspects
Ethernet GW/Switch in future EE architectures
Gateways in current/future architectures
3 Transition from Central Gateway to Backbone Arch
CAN (FD) LIN
FlexRay CGW MOST
Ethernet Central CGW Gateway Domain DCU Control Unit
Switch Today SW
CGW SW SW SW
Mid-term
DCU DCU DCU SW SW
Long-term
Characteristics of different GW types*
No. of interfaces No. of GWs Diagnostic Comments per vehicle interface Central GW any no. of <= 1 x Increasing LIN/CAN/FR no. of itfs. Local GW 1 x domain bus itf. >= 0 - n x subdomain bus itfs. Domain GW 1 x domain bus itf. >= 0 possible 1-2 x backbone itf. GW with any no. of >= 0 possible integrated LIN/CAN/FR/Eth Switch
* From the EE architecture point of view
Main GW functions (Routing, Diagnostic, …)
6 Routing Features
• Message Routing • Packet Routing • Signal Routing (eventually with signal processing) • Routing with High Priority • Different sorts of rate adaption between received and transmitted message, e.g. Periodic & Immediate Transmit On Change (TOC)
New Msg Data SOURCE
t
tCycle_S TOC Msg DESTINATION
t
tGDelay • Y Routing tCycle_D • Diagnostic Routing 7 Other Gateway Functions
• Nominal-actual configuration comparison
ECU_2 ECU_3 ECU_4 Components ECU_1 • Diagnostic tester …… Configuration – CAN and Ethernet interface provided Nominal 1 1 0 1 … Actual 1 0 0 1 … • Flash function
• Message mirroring on diagnostic bus
• Network management
• OEM specific features 8
Main principles of GW’s functionality (SW aspects, protocol aspects, AUTOSAR aspects)
9
State of the Art: Software Gateway in Central Processing Unit (CPU)
Application Software
Application Security SoftwareSignal Signal GatewaySDU Gateway GatewayTunnel GatewayTransport L3/4 SDU Gateway CPU Security Memory I-PDUs
(Software) (Hardware)
CPU Bus queue
Input schedule
Output Queues … Queues
CC 1..n NIC CC 1..n Transpor De-capsulation, t Encapsulation CPU L2 Software Ethernet MAC PDUs ECU Bus/Interfaces Bridge Security MACSec bus RBUF TBUF … schedule CC Automotive Ethernet CC HardwareHardware
ECU Bus Source: ETAS
Gateway Protocol Stack Overview
Sensor/Actuato Gateway ECU r Actuator/Senso r APP APP SIGNAL GW APP APP Signal Signal Signal IL IL SDU GW IL TP TP L3TP GW TP Phy CAN CAN FLX FLX Phy Phy Phy Phy
external cabling domain CAN Bus FlexRay Bus Discrete
Sensor Gateway Actuator
Actuator Senso ECU ECU r Actuator Sensor Source: ETAS CAN Bus FlexRay Bus Notes: IL = Interaction Layer according OSEK Comms 3.03 and AUTOSAR; adopts 11 messages/signals to PDUs AUTOSAR Aspects … App 1 App n Signal Process
Signal GW
Frame GW
Internet Protocol
• Message Routing performed in the PDU Router • Signal Routing performed in AUTOSAR COM • Signal Processing performed in Apps 12
LIN/CAN/FlexRay 2 Ethernet transport mechanisms (1722a)
Gateway Protocol Stack with 1722 Tunneling
Sensor Gateway ECU/Gateway
Sensor APP SIGNAL GW APP Signal Signal Signal IL IL SDU GW IL TP TP L3TP GW TP CAN CAN CAN* CAN* Phy Phy P1722 TUNNEL GW P1722 MACL2TP-Relay GW 802.1Q x 802.1Q x 802.3 802.3802.1Q x802.3 802.3 MAC MAC MAC MAC PHY PHY PHY PHY internal external cabling domain CAN Bus Ethernet Ethernet
Gateway Gateway Gateway Sens Actuato Sens Actuato or r or r Actuato Sensr ECU ECU ECU or Actuato Sens Actuato Sens r or r or Source: ETAS CAN Bus FlexRay Bus 1722a Ctrl Stream Data Generic Frame Format
Ethernet header AVTP control stream data header Packet info
LIN/CAN/FR message 1* …
LIN/CAN/FR message n*
* only messages of the same type allowed in one frame
1722a FlexRay PDU Format
The FlexRay PDU consists of a control stream PDU and one or more FlexRay messages Source: IEEE 1722a/D3
1722a CAN PDU Format
The CAN extended PDU consists of a control stream PDU and one or more CAN extended messages Source: IEEE 1722a/D3
1722a LIN PDU Format
The LIN PDU consists of a control stream PDU and one or more LIN messages
Source: IEEE 1722a/D3
ETAS Contribution to IEEE 1722a LIN/CAN/FR PDU Format
Optimized Gateway Messages: The transport PDU consists of a control stream
PDU and one or more LIN, CAN, FR messages Source: ETAS
GW performance aspects
GW performance aspects
The routing performance should allow all messages received on several buses with 100% load to be loss-free transmitted on the destination interfaces (which are considered to be in ideal condition)
Latency time requirements are strongly OEM specific, e.g.:
OEM1: tlatency < 2 ms
OEM2: tlatency < 500 µs
Toyota’s ultra low latency: 100µs over 5 hops, i.e. 20µs/hop
GW Network Msg RC Msg TX Msg Network A Buffer Buffer B
tnetwork tlatency tnetwork t Delay Transmission Delay Operation Delay Transmission
Startup time (time needed to start communication) Automotive Gateways
Ethernet GW/Switch in future EE architectures Ethernet GW/Switch in future EE architectures CAN (FD) LIN Daisy Chain with FlexRay optional DCU DCU DCU SW redundant path Ethernet Central CGW Gateway Domain DCU Control Unit SW Switch
Switched Architecture CGW inspired DCU DCU
DCU DCU DCU SW SW DCU DCU
Full Meshed redundant Backbone Gateway as possible Time Master
•TBD hope to get the permission from an OEM to insert a slide
Page <#> 24 Gateway as convergence device
GW DCUR
Converged data
SMR
Converged data
GW1 GW2
AFS SML
TRM
BCMR BCMF
GW DCUL
Legende: Zone oriented architecture makes use of Ethernet Video camera backbone (which connects all main areas of the vehicle) GWx Gateway + Switch XYZ ECU Inside the zone CAN/LIN networks Ethernet Ethernet AVB ensures data type convergence on CAN (FD) backbone
Thank you!