RTC Magazine

Wireless connectivity is merging with technological advancements in silicon, signaling, mass storage and software to meet the high-performance, ultra-low-power requirements for next-generation wireless systems. Embedded form factors, seeking to utilize these developing technologies to the best advantage of system designers, continue to evolve by facilitating emerging standards and providing enhanced capabilities while simultaneously reducing form factor footprints. As wireless connectivity becomes increasingly ubiquitous, the volume of embedded systems that utilize wireless is expanding, thereby perpetuating the demand for higher processing power with minimal power draw and size.

Embedded computing systems have long been tethered by wires to a stable infrastructure providing myriad connectivity options and a continuous source of power. For applications where the data is beyond the infrastructure, the solution has often been to build the infrastructure out to the data. Though this approach is feasible in locations where a wired infrastructure exists and the distance to be wired is relatively short, wired connectivity quickly becomes prohibitively expensive as the distance to be wired increases; furthermore, building out infrastructure is an entirely improbable solution in situations where there is no established infrastructure to begin with.

The solution to the limitations imposed by wires is simple—remove the wires. Though this dream of wireless connectivity has existed since the first network packet was sent over a wire, the technology required to facilitate reliable, high-bandwidth, secure data transmission has only recently emerged as a truly viable solution. The continuing evolution and adoption of wireless protocols, including Wi-Fi, WiMax, CDMA, UMTS, LTE, Zigbee and Bluetooth, along with free worldwide access to Global Positioning System (GPS) data, has unleashed an explosion of wireless consumer devices, including smartphones, mobile Internet devices (MIDs), e-books, portable media players and navigation systems. The success of these products has proven the potential for wireless applications while simultaneously fueling the expansion of the infrastructure necessary to sustain them. This has in turn opened the door for sophisticated wireless applications in the embedded systems space that take advantage of increased processing power and expanded system capabilities to revolutionize both existing and emerging embedded applications.

Design Restrictions

The freedom afforded by wireless carries with it inherent design restrictions. Lacking a constant supply of wired grid power, wireless systems typically rely on batteries. Faced with a scarcity of power, stringent control of power consumption is no longer an option but a necessity. Size is also a major design factor, as smaller sizes afford greater mobility. Support for standard interfaces and peripherals is also required to facilitate design implementation, speed time-to-market and keep system costs to a minimum. Wireless systems must also communicate over standard networking protocols and utilize advanced data compression and security functions to minimize bandwidth while maximizing data integrity and security. Wireless systems are often deployed in demanding environments subject to extreme physical and environmental stresses, which necessitates the need for ruggedized solutions with unquestioned reliability, especially in the case of remote applications.

RISC architectures, including ARM and PowerPC, have been the preferred choice for wireless embedded devices due to their ultra-low power consumption and superior performance-to-cost ratio in the light of application requirements and production volume. Success naturally breeds competition. While RISC technology continues to drive incremental increases in processor performance, CISC architectures (primarily x86), have been aggressively moving into the wireless embedded systems space through radical decreases in power consumption and package size.

Intel and VIA have been aggressively transitioning x86 technology into the wireless embedded systems space. Initially targeted at the netbook market, then at even smaller, lower-power nettop applications, x86 technology continues to find its way into smaller and smaller embedded applications.

The second-generation Atom Z5xx processor series (Figure 1) illustrates Intel’s commitment to the exacting needs of next-generation embedded systems. Optimized for low power, thermally constrained, fanless, small form factor (SFF) solutions, the Atom Z5xx series offers system designers a true embedded processor solution with processing performance up to 1.6 GHz, extended temperature operation (-40° to +85°C) and long life-cycle manufacturing support. The Atom Z5xx, along with the System Controller Hub (SCH) US15WP(T), provide the processing performance required to deliver next-generation wireless applications incorporating advanced graphics, display, video and audio capabilities, while support for PCI Express (PCIe), USB 2.0, SMBus, I2C, LPC, IDE (PATA) and GPIO provide a wealth of I/O options to support diverse system applications. Advanced power management capabilities enable power to be removed from the processor core and caches while minimizing leakage to significantly reduce idle power.