The growing demand for graphic displays from embedded systems in both the consumer and industrial space presents challenges for system designers. Fortunately a convergence of innovative connectors and low-power, highly integrated processors is enabling developers to meet that demand with small, powerful and rugged solutions.
BY BARBARA SCHMITZ, MEN MIKRO ELEKTRONIK
Regardless of the modern mobile application in question, whether it be fleet management of agricultural machines, passenger information in buses or video surveillance of trains, the trend is clear…system efficiency is a critical component to today’s embedded computing industry.
One of the key drivers in this area is the growing amount of visual data that is being incorporated into embedded systems. And graphics mean higher throughput. Slide shows and short films are not sufficient anymore; nowadays, complex, real-time 3D graphics or videos in HD quality are needed, as well. (Figure 1)
HD graphics are quickly pushing data throughput past previous levels as the expectation for high-quality visual content grows in many industries.
The proliferation of smart phones and portable tablets in the consumer market is shaping the expectations of how information is communicated in related industries as well. Visual access to data is increasingly becoming the anticipated ‘norm’, with many systems incorporating enhanced electronic elements, while integrating a display function to keep pace with growing user demands.
Grinding Through Graphics
In this new age of advanced imagery, strong processors alone are not enough; visually-intensive applications require dedicated graphics hardware. Today, many chipsets have an integrated graphics controller and, therefore, are a good, cost-effective solution for small and medium sized system requirements. As a rule, in this architecture, the CPU and graphics controller share the main memory.
But when high resolution displays—or even several screens with different, high-resolution visual content—are to be controlled at the same time, the bandwidth of this shared memory reduces both the performance of the CPU and of the graphics unit. So, independent graphics controllers with an integrated video memory become the preferred option.
If you choose an external graphics controller, the data transfer rate of the connection between the chipset and the graphics controller is the critical performance factor. For this reason, connector technologies have led the development of many of the modern buses. First, the PCI bus, then the AGP bus, and finally PCI Express were all pushed on decisively by graphics cards and the need to efficiently, and effectively, connect the CPU with the graphics component.
Data throughput is still at the forefront of connector technology, especially with the advent of high-speed serial connections quickly becoming the universally accepted data transfer route.
Contrary to other serial interconnects—such as SATA and USB 3.0 for example—PCI Express is not limited to a single lane (a differential receive and transmit signal line pair) but can combine up to 16 of these lanes in parallel to control the graphics card (PCI Express x16). Using this data transfer structure, the migration from legacy, parallel CompactPCI platforms to modern CompactPCI Serial-based ones became easier.
Graphics extensions are just one reason for the development of the CompactPCI Serial architecture. Being just as robust and modular as its predecessor CompactPCI, the enhanced specification offers even more performance and serial interfaces. CompactPCI Serial transfers the CompactPCI architecture to serial high-speed connections and offers better support for serial point-to-point structures. An outcropping of this new specification is an enhanced connector, specifically for CompactPCI Serial, that has, in turn, played an important role in the development of several embedded systems. (Figure 2)
Modern CompactPCI Serial connectors handle data rates as high as 12 Gb/s or more.
This connector scales to data rates of 12 Gbit/s and more without making space-wasting shields necessary. At the same time, it offers a much higher density than the conventional 2-mm signal connectors typically usually used for CompactPCI. To make sure that conventional CompactPCI interfaces like PCI Express, SATA and Base-T Ethernet are not supplied alternatively, but in parallel—meaning at the same time—connectors with high contact density on the system slot interfaces must be used.
The new connector features enhanced thermal management properties and a rugged housing that combine to significantly increase reliability, enabling CompactPCI Serial to be considered for rugged applications not typically associated with its legacy specification.
But, the connector offers advantages that are more far-reaching than just facilitating data throughput in CompactPCI Serial systems. In fact, it has proved very useful in a new line of box and panel PCs from MEN Micro. The uniqueness of this computing family, and why the connector is so beneficial, is that the external interfaces are separated from the main board. Depending on end user requirements, many different versions based on the system core are possible.
The Whole Package
These industry-ready box and panel PCs use a flexible, modular concept that allows different processor performance, interfaces and power supply types as well as display interfaces and system sizes to be developed easily and cost-effectively.
The pre-integrated display computers are especially useful in meeting the changing demands of the many industries that are increasingly incorporating visual technologies. These systems are both modular, so that unique attributes can be tailored to specifically match an application, as well as rugged to withstand wide temperature ranges, severe shock and vibration and harsh environmental elements, such as dirt, dust and humidity. For example, the innovative modular concept that separates the external interfaces from the main PCB offers the highest flexibility. This way, the interfaces can be configured individually and adapted quickly to all requirements without additional development overhead.
A major area where panel PCs are currently deployed is in mass transportation. They cover a diverse range of functions from infotainment systems, digital signage platforms, ticketing machines interfaces to driver desk applications and passenger area supervision on a vehicle or the platform itself. (Figure 3a & 3b)
Consumer-facing industries, such as mass transportation, are some of the more heavily-invested forerunners to incorporate advanced graphics in computing technologies.
The design is always accomplished without fans, using conductive cooling to spread the dissipated heat to the outside of the housing—the box computer itself serves as the heat sink. Thanks to this conduction cooling, the device operates at temperatures from -40°C to +85°C. The electronic components are fully designed for demanding environments and even resist shock and vibration. Standard versions comply with the EN 50155, class Tx railway standard and are prepared for e-Mark certification.
Increasing Graphics Requirements
Functioning as independent computers, box PCs take on a variety of tasks. As graphics data becomes increasingly more important in these tasks, the connector needs to keep pace with data transfer demands.
Offering medium to high graphics performance, these computers are ideal as onboard computers or content servers. They can communicate with the control room via a wireless connection and send information to several displays. After all, DisplayPort supports HD resolutions of 1920×1080 pixels with a cable length of 45 feet.
Therefore, many applications in buses and trains are implemented using this type of box computer, making the connector’s ruggedness a critical feature to ensure reliable operation. A single computer controls, for example, two monitors in a bus via DisplayPort. They keep the passengers informed on the course of the route and display the stops and stop requests. In the meantime, informational videos are shown.
Whenever the train is in the depot, the data is updated via WLAN. The connector is constantly moving data from the external graphics platform to the main processing hub within the system.
One Chip, Two Functions
Wherever more performance is required, the scalable concept of these box PCs is of great benefit. AMD is way out in front of this concept at the moment. The Embedded G-Series combines each single- or multi-core CPU with a graphics processor of the Radeon range.
This fusion concept of AMD’s Accelerated Processing Unit (APU) chip is a critical component in the pre-integrated display PC concept. As its name suggests, the chip enables enhanced processing performance with exceptionally low power consumption. The APUs make computing performance scalable thanks to their compatibility. A resolution of 2560×1600 pixels on several monitors is possible, even on devices suitable for vehicles.
By housing both the actual x86 CPU and a GPU from AMD’s Radeon range, AMD’s APU reduces the common 3-chip solution—consisting of a processor, Northbridge and Southbridge—to a small-footprint, 2-chip solution while providing the performance level of a dedicated graphics card. As an example, AMD’s Embedded G-Series 1-GHz dual-core G-T40R with integrated Radeon HD 6250 graphics processor has a maximum thermal design power (TDP) of just 5.5 watts.
More powerful processing capabilities are easily incorporated into the modular panel PC design concept, with advanced embedded APUs, such as the G-T48N that combines a 1.4-GHz dual-core CPU and a Radeon HD 6310 dissipating up to 18 W, serving as the heart of a system.
Thanks to advancing technologies that are keeping pace with growing data demands, users have many possibilities to effectively employ enhanced graphics performance without the frustration of data bottlenecks. And by using standard components that can be flexibly integrated together, innovative ideas and technologies make cost-effective and robust graphics solutions possible.
Blue Bell, PA.