Graphics Display Controller for Automotive Applications Eisuke Miura Makoto Nakahara Hidefumi Nishi Fujitsu has had graphics display controller (GDC) products on the market for years as system chips for use in in-vehicle information devices. More automobile instrument cluster and center display systems are now using full-color liquid crystal displays, and there are often multiple displays in a single vehicle. Keeping pace with this evolution of devices, Fujitsu developed the MB86R1x series of systems-on-a-chip (SoCs), which integrate a high-performance microproces- sor with a proprietary graphics processing unit (GPU) and various in-vehicle network functions. Here, we briefly describe the latest trends in automobile information devices and systems and present an overview of the MB86R1x series of SoCs, our most recent automotive GDC product line. We also explain the technologies developed for these systems, including the GPU, image processor, and in-vehicle network. 1. Introduction comprehensive and integrated electronic information An automobile instrument cluster conveys to the system. Future development is expected to extend driver information on vehicle operation, such as vehicle the provision of services and information to use of the speed and fuel level. The main instrument is tradition- Internet and the cloud. ally a needle-type speedometer. Light emitting diodes Fujitsu offers a commercial graphics display (LEDs) and small monochrome liquid crystal displays controller (GDC) that is well suited to such an inte- (LCDs) display various types of information using char- grated electronic information system. In this article, acter patterns or text. Needle-type instruments are we describe the latest trends in automobile informa- increasingly being replaced with relatively large mono- tion devices and systems, present an overview of the chrome or color LCDs that use graphics to provide more MB86R1x series of systems-on-a-chip (SoCs) designed information in a way that is more readily understood. for integrating ECUs, and explain the technologies de- Large LCD screens are also used, and some products veloped for these systems. feature even the speedometer and other instruments implemented as drawn graphics. 2. Trends in automobile information Electronic information systems that provide driv- devices ing support functions such as car navigation systems An example configuration of a current-generation that use color map displays and video monitoring sys- automobile dashboard is shown in Figure 1. The instru- tems are growing in popularity, and we are beginning ment cluster displays the vehicle speed, fuel level, gear to see multiple color display devices in a single vehicle. position, and other information needed for operating Such systems are generally installed as independent the vehicle. The head-up display shows the speed electronic control units (ECUs). Integration of these numerically, turn signal indicator, night vision images, systems would make them easier to use. Including and other information needed for quick decision mak- the car navigation display, the video display, and the ing. It is projected as video onto the windshield. The other displays in the instrument cluster would minimize center display presents map-based navigation informa- movement of the driver's line of sight and provide a tion and in-vehicle entertainment using audio-video FUJITSU Sci. Tech. J., Vol. 49, No. 1, pp. 23–28 (January 2013) 23 E. Miura et al.: Graphics Display Controller for Automotive Applications Head-up display Information needed for Center display quick decision making Information related to comfort Instrument cluster Information needed for driving Figure 1 FigureExample 1automobile dashboard confi guration. Example automobile dashboard configuration. Center display Instrument cluster Head-up display Map navigation Internet Video monitoring Vehicle area network Integrated HMI System chip Telematics Video monitoring Navigation (TV/audio) system Driving assistance Figure 2 IntegratedFigure HMI 2 system. Integrated HMI system. equipment for comfortable driving. This arrangement management of driver operations and control of the ve- was designed in consideration of the needs of and ease hicle equipment, enables various types of information of use by the driver and passengers. processing to be effi ciently performed, and enables the An example confi guration of a next-generation results to be displayed using a single interface. It also integrated system as described above is shown in enables fl exible presentation of navigation information Figure 2. In this human machine interface (HMI) not only on the center display but also on the instru- system, the instrument cluster, head-up display, and ment cluster or head-up display when appropriate. center display are implemented as an integrated sys- Such an integrated system requires a system chip tem rather than as independent ECUs. In addition with multiple input interfaces for vehicle information, to lowering system cost, this integration unifi es the navigation information, camera images, etc. It must 24 FUJITSU Sci. Tech. J., Vol. 49, No. 1 (January 2013) E. Miura et al.: Graphics Display Controller for Automotive Applications also have multiple display outputs and be capable of For example, a 360° video system composes and high-performance graphics drawing and image pro- transforms the image data from four video cameras cessing as well as display control. mounted on the front, back, left, and right sides of the Future development will enable this integrated vehicle into a single image in real time and displays HMI system to provide a graphical interface for driver this image on a monitor. This video processing can input operations using devices equipped with touch be implemented on a single chip. (See “Automotive panels and haptic feedback instead of the many types Graphics SoC for 360° Wraparound View System” in this of switches that are currently used. issue.) The integrated HMI system is easy to implement 3. MB86R1x series of SoCs along with other automobile information systems due A block diagram of the MB86R1x series SoC to the provision of an APIX2 high-speed image transfer developed by Fujitsu for the instrument cluster, car nav- interface, a controller area network (CAN) in-vehicle igation, and integrated HMI system described above is network, and a media local bus (MLB) that complies shown in Figure 3. An ARM CortexTM-A9 CPU serves as with the Media Oriented Systems Transport (MOST) bus the high-performance core. The graphics unit consists standard for in-vehicle multimedia networks, as well as of a Fujitsu graphics processing unit (GPU) and an inde- USB, secure digital (SD), and Ethernet general-purpose pendent dedicated 2D graphics engine. peripheral device interfaces. The graphic unit includes a four-channel video input function and a display output function that can 4. Developed technologies drive up to fi ve screens. It supports the high-speed This section presents a broad explanation of the video processing needed for the inputs and outputs. technologies we developed for the MB86R1x series of Multimedia I/F Standard I/O Flash/RAM I/F ARM CortexTM-A9 ARM CPU Neon SMID I-cache D-cache L2 cache Video input Graphic unit Video output Video input GPU Image Video output processor Video input 2D graphics engine Video output Video input MOST 25/50 CAN Ethernet FigureFigure 3 3 MB86R1xMB86R1x block blockdiagram. diagram. FUJITSU Sci. Tech. J., Vol. 49, No. 1 (January 2013) 25 E. Miura et al.: Graphics Display Controller for Automotive Applications SoCs and other GDC products. used to implement the graphics engine at low cost. The engine uses the sprite drawing method, which 4.1 GPU does not require a frame buffer. It can display up to The GPU technology we developed supports the 512 sprites, each of which can be a pattern of up to OpenGL ES 2.0 industrial standard for graphics applica- 512 × 512 pixels. There are functions for vertical and tion programming interfaces (APIs). The GPU can draw horizontal sprite reversal and rotation by 90°. There is 10 million polygons containing 400 million pixels per also an animation function for automatically updating second, so it can produce high-quality graphics at high the pattern and an anti-aliasing function that is spe- speed. cialized for drawing fonts. This GPU has a unified programmable shader architecture. The 3D graphics processing includes a ver- 4.3 2D graphics engine tex shader, which computes shading in units of vertices, The 2D bit-map graphics engine technology we and a fragment shader, which computes color in units developed provides image transformation functions of pixels. This architecture describes hardware that sup- for image rotation, enlargement, and reduction for any ports both a vertex shader and a fragment shader and angle or size. It also provides, for example, a function shading algorithms that are programmable. This en- for head-up display. Advanced image filtering func- ables a high degree of freedom for user-written shader tions work together with the transformation functions programs, facilitating the attainment of the desired to maintain high quality in the transformed images. drawing results. The programmable shaders can also The 2D graphics engine can operate independently be used for numerical operations with a computational of the GPU, enabling high-speed hybrid HMI system performance of up to 17 GFLOPS. processing in which 2D graphics functions are used, for The GPU also supports two other functions. example, for drawing a speedometer and 3D graphics 1) Multi-sample anti-aliasing (MSAA) functions are used for drawing the outside view of the This function achieves an image smoothness be- automobile, as shown in Figure 4. yond the resolution of the display by reducing 'jaggies' (a zigzag pattern at the edges of an image). 4.4 Visibility enhancement unit 2) Polygon drawing The MB86R1x series is also equipped with a vis- This function supports high-speed drawing using ibility enhancement unit (VEU), a specialized image simple commands for producing the polygons used, for processing engine that was developed by applying example, in navigation maps.