Electronic devices are rapidly evolving, especially automotive display systems, with video and video processing becoming some of the fastest-growing technologies in automotive applications. Typical application requirements include lane keeping assist, driver monitoring, night vision, and in-vehicle entertainment systems. When designing an automotive video system, several aspects of the system architecture need to be considered: First, the system's function—whether it's designed for processing video information for safety systems, processing streaming video data for in-vehicle entertainment systems, or a combination of both. Second, the type of interconnect and the speed of the video system devices. Other factors to consider include the number of video sources, display outputs, the distance between different devices in the system, the wiring scheme used, and the overall system cost. Programmable devices are becoming increasingly attractive to engineers designing automotive electronics due to their high integration and flexibility, low power consumption, wide operating temperature range, and continuously decreasing price. This article will primarily introduce how to design an automotive display system using Lattice's programmable devices. Interconnection of Electronic Devices In automotive electronic devices, the interconnection of various information sources can adopt several topologies, namely star, bus, and ring structures. These topologies are shown in Figure 1. A star topology is a one-to-one connection system, where external devices connect to a port on the video controller. Communication channels can be bidirectional or unidirectional. [align=center]Figure 1: Several Topologies for Interconnecting Automotive Electronic Devices[/align] A bus topology is a one-to-many connection, where a single device can connect to the bus. Devices on the bus must have a local controller to coordinate when and how they communicate. This type of system is easily scalable because each device has a unique address. In a ring topology, each device has a unique address, in addition to a local data controller and media transceivers for connecting to the ring. When a display device transceiver receives information from the previous device, it checks its own address in the data packet. If the address matches, it processes the data or command; if the address does not match, it forwards the data packet to the next device in the ring. To enable various devices to transmit audio and video packets, automotive ring buses for entertainment are designed with high bandwidth so that viewers can watch in real time. As shown in Figure 1, a video controller is required in all topologies. Image Capture and Display Effectively ensuring image capture and processing is crucial. Several solutions will be introduced below. In several examples of intelligent image capture systems shown in Figure 2, information is transmitted from the vehicle's multimedia bus to the video controller. A ring or bus architecture using MOST and D2B protocols is typically used. [align=center] Figure 2: Three Intelligent Image Capture Systems Using Different Processing Devices[/align] In these three examples, the MT9V111/125 is an image sensor suitable for automotive applications. Example 1 uses a microprocessor-based system for control and video data processing before data is sent to the interface of the display subsystem. Example 2 uses a low-cost flash-based CPLD for video processing. Example 3 uses an SRAM-based FPGA device. In all the above examples, the transmitted information is processed by a processing unit. The programmable logic devices used in the latter two examples demonstrate the flexibility of hardware reconfiguration. In particular, Example 3 uses the Lattice Micro8 microprocessor core from Lattice in its FPGA, thus providing greater flexibility. One method for transmitting the captured images is to convert the parallel video data into a serial stream and transmit it over a single-pair twisted-pair LVDS interface using 8b/10b encoding. This interface embeds the clock into the data stream, reducing the number of wires required to transmit signals to the video controller. At the receiving end, the system needs to process the data to return it to its original form. Figure 3 shows four examples of LCD displays. The first three examples all use SERDES circuitry to convert signals, with example 3 using an SRAM-based FPGA with integrated SERDES functionality. This example uses a LatticeECP/ECP2 FPGA, which, because key timing parameters are embedded in the device, eliminates the need for designers to spend significant time and effort on this task. [align=center] Figure 3: LCD Display[/align] The LatticeECP2 and LatticeECP2M series redefine low-cost FPGAs, offering more excellent FPGA features at a lower cost. These devices contain sysDSP blocks and pre-built source-synchronous I/O. The LatticeECP2M has up to 5.3Mb of RAM blocks, while the LatticeECP2 has up to 1.1Mb of RAM blocks. The LatticeECP2M also features 3.125Gbps embedded SERDES, supporting PCI Express, Ethernet (1GbE and SGMII), and several other standards. By integrating features and performance previously only available on high-cost, high-performance FPGAs, these product lines expand the application range of low-cost FPGAs. The LatticeMico32 is a 32-bit RISC soft microprocessor optimized for Lattice FPGAs. Combining the LatticeECP2M with the open-source LatticeMico32 soft processor allows the LatticeECP2M to implement complete video controller functionality (as shown in Figure 4). Internal peripherals communicate via dual WISHBONE buses. Timers, DMA, memory controllers, general-purpose I/O, serial peripheral interfaces, and UARTs can all be connected to the LatticeMico32. [align=center] Figure 4: Implementing complete video controller functionality using LatticeECP2M and LatticeMico32[/align] Summary Programmable devices are particularly well-suited for handling various changes (such as constantly evolving and emerging standards) and can quickly implement new versions of standards. Furthermore, programmable devices offer advantages such as low cost and long lifespan, meeting the requirements of in-vehicle electronics matching the lifespan of the vehicle, and designers can easily upgrade, maintain, and update their products.