Mentor Graphics: Reference Design for Advanced In-Vehicle Systems
It’s more difficult for automakers today to innovate, lower the cost of parts, and get to market quickly. Drivers and passengers alike expect the capabilities of smartphones and tablets to be part of in-car Electronic systems.
In recent years, some functions that were originally introduced as high-end and top models have become cheaper, and more and more cars are equipped with these functions.There is a new trend of competing car brand manufacturers using the same technology — such as infotainment GENIVI Linux platform. but for Attract and retain customers for innovation and OEMDemand for (OEM brand) differentiation remains strong. Combining proprietary, in-house developed embedded software with open source packages is an increasingly sought-after solution.
Mentor Graphics developing“proof of concept“refer to The platform has the flexibility to be tailored to a specific design, providing customer-requested functionality in a secure, automotive-grade code package.This special platform can be designed according to current market trends and includes: Driver Information Module (DIM); automotive infotainment; smartphone and tablet integration; advanced driver assistance systems (ADAS) functionality; based onAUTOSARStandard communication capabilities.By introducing on an automotive hardware reference platform Type-1 Embedded virtual machine (embedded hypervisor) The core design implements the integration of this technology, in this case using the most recent Mentor Graphics acquired XS Embedded GmbH (XSe®) of automotive grade AXSB®.
This design faces several challenges, including maintaining acceptable performance for each running application, sharing available hardware resources, and managing secure inter-domain communications.
meet concept requirements
LinuxIt has been gradually accepted by automakers as a powerful multitasking operating system that can run high-end graphical automotive applications and support a variety of peripheral devices such as cameras,USB equipment, audio and multimedia capable equipment.driver information module (DIM), vehicle alarm systems and controls are less demanding on computing resources, but still need to ensure performance and a stable Display showing important safety status information.To achieve these functions, a secure real-time operating system is used (RTOS) very suitable.Vehicle Control Domain Network (CAN),FlexRay or other network-acquired information can be provided to the real-time operating system.
The design requirement was to combine these two separate operating systems (Linux and RTOS) and running applications on a hardware reference platform and can be AUTOSAR 4.0.3 Standard interface (picture1)accomplish CAN(Vehicle Control Area Network) communication. It is a fact that vehicle designers must integrate consumer electronics,95%Above the market by offering to Apple iOS and google Android Device support meets this need. Other standards are emerging in this area,Mentor The proof-of-concept platform includes MirrorLink support,Apple CarPlay and Google Android Auto.
Reduce element cost and enable hardware consolidation by choosing a multi-core reference platform. This reduces the number of vehicle components and the associated cost of electronic harness design.Used XSe AXSB platform powered by Texas Instruments (Texas Instruments) J6 multicore CPU(CPU and Renesas Electronics Corporation (Renesas) V850 MCUs(Microprogrammed controller).AXSB Also includes many Ethernet-specific(ethernet)serial port /USBradio tuner, reversing camera input circuit and CAN Transceivers and many other supporting peripheral components.a based on Yocto and meet GENIVI of Linux The distribution has been highly optimized for this platform for fast boot.Also, some important Linux components such as audio management and graphics management have been“Reinforce“.Improved memory components and bootloader allow Linux The operating system is up and running in under two seconds, meeting automaker requirements for infotainment and navigation systems.
Mentor Graphics of Nucleus® RTOS(Real-time operating system) takes up less resources and starts quickly, so it was selected as the driver information module (DIM) operating system.The operating system is highly configurable and has a module for popular driver information(DIM)Graphical support for standard interface of application software Open GLES2. Using remote protocol messages (Remote Protocol Messaging, RPMsg) for stable communication, allowing the driver information module (DIM) software stack to the infotainment system and AUTOSAR The software stack transmits real-time data.
Consumer Electronics Integration
What automakers cannot escape these days is that — Requires support based on Apple iOS system and based on google Android system equipment. Smartphone and tablet manufacturers typically have innovation cycles of less than a year, so there is a need for a universally supported method of connecting these devices to in-vehicle electronic systems that can be used throughout the life of the vehicle.Early systems used bluetooth (Bluetooth)but Bluetooth technology does not have the bandwidth for multimedia integration, nor does it support video streaming for rear-seat entertainment.USB is a recognized connection method,Wi-Fi(Wireless network) In-vehicle links are increasingly being used to transmit audio-visual information, while providing in-vehicle hotspots to support multi-device customers.Forming the Car Connectivity Alliance (CCC) is to promote and propose MirrorLink Become the industry standard method for integrating smart devices.with the help of MirrorLink The phone-based application software can be accessed, displayed and controlled remotely from the infotainment management device.Performers can control which applications are available and how they can be accessed — Whether through the touchscreen user interface or mounted on the steering wheel button.Multiple equipment manufacturers and vehicles OEM(Original Equipment Manufacturer) is the Car Connectivity Alliance (CCC) Members, several products incorporating this technology are already in production.Apple (Apple) Proprietary CarPlay solution.
Smart device integration should be part of any new car these days.It gives drivers instant access to contacts, music, videos and favorite apps, as well as connecting with smart devices4G/LTEnetwork. This allows real-time access to cloud services such as navigation, concierge services, personal email and more.Mentor Reference design includes implementation MirrorLink standard and can pass10The inch touchscreen interface performs all smartphone functions.
Figure 1: Reference Design Outline
Multiple OS Architectures
A virtual layer that runs a virtual machine is a way to allow Linux and Nucleus RTOS A neat way to run concurrently on one hardware platform.Each operating system runs on a dedicated virtual machine and is shared AXSB Hardware resources available on the platform.Communication between different operational domains can take advantage of RPMsg The protocol is performed in a controlled way so that some data can be shared between applications. You can also manage resources and deny access to certain system functions by setting permissions. This allows for some degree of isolation when untrusted or unauthenticated applications may be installed or downloaded in the infotainment system.
The boot sequence has also been carefully considered.usually in the car CAN bus communication should be in 50ms internal activation, but also requires the infotainment and driver information modules to initialize quickly.In this reference design, based on AUTOSAR of CAN The communication stack is in Renesas V850 MCUs complete initialization on the J6 multicore CPU run simultaneously.RPMsg The communication engine starts quickly to communicate early traffic status between domains ( picture 2 ).
picture 2: Multi-Domain Boot Architecture on a Single System-on-Chip (SoC)
Building an infotainment system
The proof-of-concept reference design includes functional examples including software radio tuners, rear-view camera inputs, multimedia video and audio players, and in-vehicle system functions such as HVAC(HVAC) control and tire pressure monitoring system.The functions involved in the tire pressure monitor are representative. Its data source comes from a certain part of the far end of the car. When the low pressure or the tire is completely flat, the relevant information must be passed first. CAN The bus is sent and displayed immediately on the driver information screen. Because of the Display priority, the alert screen overlays the default infotainment home screen. use CAN information generator (ETAS BusMaster simulator) to test the system, see picture 3 .
picture 3:useETAS BusMaster generate CANTraffic Test Reference Design
Several other tools are used to adjust the boot sequence, including Mentor Graphics® XSe XSTrace® and Mentor Graphics Sourcery™ Analyzer. By monitoring initialization and power-on sequences, drivers and processes can be reordered and valuable time saved. Power-on optimization is an iterative process where unimportant system tasks and processes are moved out in time to make way for important car features to appear earlier.
to ensure DIM The frame refresh rate reaches60frame/sor faster also using graphics–Performance tuning tool.To ensure in-car infotainment (IV) and DIM The module receives graphics bandwidth at critical moments,GPUThe (graphics processor) shared architecture includes load balancing and resource optimization.This process involves GENIVI Wayland element,Open GLES2 Participating multi-layer tuning, and a proprietary display tool layer for displaying on-screen images. Analyze the trade-off between screen resolution and performance to ensure better visibility and better performance than specs.
The end result is a concept design that we believe fits with existing market trends and has the potential to save time and development cycles in today’s competitive automotive market.
In today’s fast-moving automotive electronics market, designing from scratch is no longer advisable — It took years of research to find the right solution.Using pre-established reference design concepts, designers can select nodes where difficult performance and integration problems are solved as design starting points, and then add their ownIP(Intellectual Property) and eventual customization requirements, thereby reducing time-to-market and delivering functionality directly available to users to meet current market needs.
Mentor Graphics and Automotive Division XS Embedded Groundbreaking use of industry-standard software and hardware componentsnear-A-Sample(closeAlevel experiment) platform.The design will be held in Las Vegas2015Consumer Electronics Show (2015 Consumer Electronics Show)Nuremberg, Germany Embedded World and other major events held around the world.
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