Reference Designs Using FPGAs to Drive Automotive Infotainment Electronics

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Reference Designs Using FPGAs to Drive Automotive Infotainment Electronics [Copy link]

Automotive entertainment electronics has driven the rapid development of functions and capacity, prompting designers to make comprehensive considerations on performance, cost and flexibility. Unlike other automotive electronics fields, multimedia graphics applications are highly visual, their requirements are changing, and in many cases there are no established standards. Automotive designers need a solution that can provide the most flexibility, best performance and controllable cost. Programmable logic, especially field programmable gate arrays (FPGAs), is such a solution.

　　In the past, application-specific integrated circuits (ASICs) were able to provide manufacturers with a cost-effective chip solution, so ASICs were generally the semiconductor of choice for automotive graphics applications. However, the rising cost of ASIC development, the requirements for lower volume prices, fast time to market, and the increase in functional complexity may herald the end of the era of ASIC dominance in the automotive market. Top automotive suppliers are looking for the most cost-effective design platform with the power and flexibility to meet the needs of increasingly complex automotive digital systems.

　　Application-specific standard products (ASSPs) are an alternative to ASICs in the automotive and consumer markets. The main advantage of these products is low cost. However, ASSPs have hidden costs, such as finding an ASSP that has all the functions required without having to add external logic, software, or other ASICs or ASSPs. Also, as requirements change, ASSPs may not be needed in the early stages of a design, and once a design is in production, they are no longer used.

　　FPGA能够显著缩短工程开发时间，降低多芯片重复使用成本，成为汽车图形应用中替代ASIC和ASSP的功能强大而又灵活的解决方案。ASSP可能会丢失所需功能，ASIC则有随着设计修改而必须重制的风险，而FPGA在设计过程中，可以进行编程，并根据需要重新编程，实现更快速的原型设计，加快产品面市。如果需求变化，即使是器件已经在车辆中投入使用了，FPGA也可以现场进行更新。FPGA不存在预先的ASIC流片（NRE）成本以及最小订购量问题，也不存在ASSP相关的潜在成本问题，它是系统设计最具成本效益的选择。而且，FPGA在通用硬件平台上能够重复使用的能力显得非常重要，使设计人员能够生成不同的系统，凭借一个基本设计便可以支持多种功能，从而降低制造成本。

　　FPGA reference design advances automotive graphics technology

　　Infotainment applications require increasingly complex graphics processing capabilities. This processing can be implemented in high-end processors and DSPs, but at the expense of extremely high cost, complexity, and power consumption. FPGAs can be added to the system to reduce the overall cost, complexity, and performance requirements of the graphics system. Figure 1 shows a standard graphics reference design that hosts a video input and overlays other images displayed on an LCD screen.

Figure 1: Automotive graphics control system using FPGA and host processor

　　This reference design implements a video input module and LCD graphics controller in an Altera Cyclone? FPGA, demonstrating the power and flexibility of FPGAs in low-cost applications required by the automotive market. The reference design runs on an Altera Nios II embedded processor development board and incorporates modules for implementing camera/video input and output display driver circuits.

　　The video input module includes a front-end camera interface and IP for color space conversion, adjustment and scaling, as well as a video memory interface. The LCD display interface includes IP functions for controlling translucency between different layers and between images. These input and output control modules are part of the Altera SOPC Builder system, which is used to seamlessly connect all IP modules. A subset of the OpenGL-E graphics library runs in the host CPU. The library provides all functions for processing and representing bitmaps, frame buffer access, and drawing graphics primitives.

　　Since these extended graphics applications are computationally intensive when performing perspective operations, rotations, drawing lines and polygons, texturing, and similar tasks, a very powerful host CPU may be required to implement the OpenGL graphics library. The FPGA can be used as a co-processor architecture to offload algorithmic functions that normally consume a lot of CPU performance from the host CPU.

Figure 2: Graphics control system with hardware acceleration coprocessor

　　Figure 2 shows an example of adding a graphics acceleration coprocessor to the reference design system. The coprocessor can host a variety of algorithms, such as:

　　●Block image transfer (BLIT) operations such as direct blit, stretched blit, transparency, bilinear filtering, per-pixel alpha, shading, anti-aliasing

　　●Drawing straight lines of arbitrary width, rounding, truncating, alpha gradient, blurring (blurring) of image edges
　
　　●Drawing polygons such as triangles and quadrilaterals, alpha gradient, blurring (blurring) of image edges
　　
　　●Drawing circles, ellipses and quadratic curve sections
　　
　　●Generate quadratic and cubic Bézier curves

　　加入协处理器后，对主机CPU的CPU要求会显著降低。当然会使用更多的FPGA资源，但是系统设计人员可以自由选择在硬件中采用何种算法，具体在软件中采用哪种以优化大部分关键系统要求（速度、功耗、成本等）。

　　We can extend this offload paradigm further and place other processing tasks in the FPGA using a processor implemented in the FPGA. This also has the advantage of reducing system components and external host CPUs. Figure 3 shows how the graphics reference design uses a Nios II processor to implement other software-controlled tasks such as anti-aliasing and OpenGL compatibility in the FPGA.

　　

Figure 3: Graphics control system implemented in FPGA with host CPU

　　Platform concept - various small changes

　　By using FPGAs in automotive graphics systems, the same platform can be used to address different market needs. Figure 4 shows how you can start with a single common platform and make multiple variations to meet different market needs without having to respin the ASIC or build and debug a new board.

　　The various automotive reference designs described in this article illustrate how this concept works. A single working reference platform is used to implement multiple variations of the graphics controller module, depending on market requirements. By using standard IP and reference designs, development teams can focus their efforts (and expenses) on how to keep their products ahead of competitors and meet customer requirements, rather than on basic programming. Furthermore, using an FPGA does not preclude the use of an ASIC later on. Since all the basic IP can be reused in future device families, a design implemented in an FPGA can be ported to a structured ASIC such as an Altera HardCopy device or a fully custom ASIC.

　　in conclusion

　　In the engine compartment, passenger compartment and external diagnostic systems, FPGAs provide a flexible, low-risk path for successful system design - reducing manufacturing complexity and achieving optimal cost-effectiveness. FPGAs can be used as simple glue logic and interface bridges between different components - helping to achieve communication between standard components, microprocessors and system buses. FPGAs can also expand features and integrate core system functions to replace ASSPs and ASICs.

　　When considering the increasing complexity and time-to-market pressure, although automotive applications require suitable ASICs to achieve high-volume products, FPGAs can still meet or even exceed total engineering cost targets. The low-cost structure and rich device resource combination implemented in FPGAs enable designers to provide comprehensive and economical solutions for such high-volume product applications. Moreover, due to the flexibility of FPGAs, these designs can be quickly improved to meet changing market needs and refine products without expensive redesign of the overall platform.