No Shortage of Controller Innovation
8- and 16-bit MCUs Provide a Full Spectrum of Features and Costs
Increasing complexity in embedded applications is expanding the need for high-performance 32-bit MCUs, but controller vendors continue to innovate in 8-bit and 16-bit product lines. With this innovation, along with ever-present price pressures that force developers to think long and hard about specifying products with more features than are really necessary, 8- and 16-bit MCUs have kept their strong foothold in the embedded market. In fact, while 8- and 16-bit MCUs continue to dominate in automotive and industrial applications, industry experts see plenty of opportunities in a range of new low-power applications as well. EE Catalog talked to Fanie Duvenhage, director of applications, architecture and marketing, Microchip Technology, Inc.; Scott Avery, director of field marketing, Atmel Corporation; Steve Darrough, director of worldwide marketing, Zilog; and Geoff Lees, vice president and general manager of MCU, NXP to get their views.
EE Catalog: With today’s higher performing 8-bit controllers and the increasing availability of lower-cost 32-bit controllers, what’s the future of 16-bit MCUs?
Fanie Duvenhage, Microchip Technology: The microcontroller market is a continuous spectrum, with a multitude of attributes and requirements that balance the levels of integration, power consumption, computational efficiency, real-time performance, robustness and, ultimately, cost. No single architecture or even group of products can meet all of the requirements of this market.
The width of a microcontroller’s data path is not the most important criteria when selecting a device. For example, there are many cases where the combination of computational performance is too high for an 8-bit microcontroller, and the static power requirements are too low for a 32-bit microcontroller.
Scott Avery, Atmel: We expect the design opportunities for 16-bit controllers to slowly decline moving forward. There are 8-bit architectures available today that offer the same feature set, performance and lowpower consumption. Over the last several years, the market has seen the introduction of highperformance 32-bit architectures that are competitively priced against 16-bit controllers. Because of the need for higher performance and to future-proof their investment, developers are starting to migrate to 32-bit solutions.
Steve Darrough, Zilog: Initially as needs for 8-bit microcontrollers have evolved and with the emergence of 32-bit solutions, the 16-bit arena was overlooked to some extent. Now, however, as these application thresholds blur, the pendulum has come back to 16-bit in several areas; particularly the industrial segments found they are well suited for their design needs. This gets designers a new, broader solution with increases in memory options, and in some cases even supports a 32-bit architecture.
Geoff Lees, NXP: Today’s 16-bit solutions are trapped in a “gap” where they can’t compete on pricing against the 8-bit parts but don’t offer enough performance against the 32-bit solutions. Looking towards the future, the 16-bit MCU market will continue to see feature competition from 8-bit solutions and pricing competition from 32-bit solutions. 32-bit MCU vendors like NXP continue to improve the system architecture and process technologies of new 32-bit microcontrollers, thus reducing the system’s power consumption and silicon cost. On the other hand, many 8-/16-bit MCUs vendors are slowing down the rate of adoption of cutting-edge process technologies because the smaller reduction in die size no longer offers significant cost reductions. We think 32-bit solutions will offer more “bang for the buck” compared to 16-bit MCUs, due to similar levels of low-power performance (in both active and power-down modes), more capable and configurable peripherals,and with competitive pricing.
EE Catalog: What are some of the challenges developers face in migrating from 8- or 16-bit controllers to 32-bit controllers?
Duvenhage, Microchip Technology: The broad concept that 8- or 16-bit microcontrollers automatically migrate to 32-bit is not realistic. Developers select the best microcontroller for the application based upon design requirements, so migration should be evaluated in the context of the driving force behind the migration.
Many designs, for example, move to 32-bit microcontrollers because advanced connectivity such as Ethernet is easier to implement, due to its larger memory requirements. In this case, developers have to adapt to a different development philosophy, relying much more on preexisting libraries and how to integrate these with the rest of the application.
In general, developing with 32-bit microcontrollers requires much more of a software focus than developing with lower end microcontrollers. Developers often utilize real-time operating systems and more complex software stacks, and rely more heavily on the inner workings of the software development tools such as compilers, when working with 32-bit microcontrollers.
There are hardware differences associated with most 32-bit microcontrollers, which usually operate at lower voltages and higher frequencies. Additionally, there is generally more complexity when interfacing to the real world with applications involving 32-bit microcontrollers. 32-bit microcontrollers also often utilize external memories.
Avery, Atmel: Basically, when there is a need, developers will always lean towards higher performing MCUs but will also factor in the time-to-market, time-to-revenue and how much of an investment is required to support this migration. The biggest challenge is the tools. Normally new hardware tools are needed, as well as software expertise; 32-bit code is more complex.
Darrough, Zilog: Several considerations need to be reviewed and factored in moving into the 32-bit arena. Certainly it opens up a new list of more sophisticated applications, but also in many ways it changes the way microcontroller companies look at how they position their products. Tools are one area that have significant differences from previous in-house solutions and add several considerations. Developers now have many choices that are all competent that are not tailored to just their own product line. This complicates and levels the playing field. Companies need to consider the commodity factor as well, with such focus on 32-bit and such great support, there are challenges to differentiate. Many companies address this through embedded software that is specific to certain application segments.
Lees, NXP: The No.1 challenge is the familiarity of the development environment. Some customers are worried about potentially expensive investment for setting up a 32-bit development platform and the associated learning curve. To help customers lower their entry barrier, NXP developed a tool chain with associated development board. There are also organizations like mbed, which offers a free online IDE and complier for rapid prototyping using ARM based 32-bit MCUs. With these low-cost tools, developers can quickly and easily become familiar with 32-bit development tools, easing the migration from 8-/16-bit designs. It’s also worth mentioning that 32-bit ARM-based solutions share instruction sets among lowcost, energy-efficient solutions and high-performance solutions, and some of them are even pin-compatible. Thus, once adopted, customers can easily migrate among the different 32-bit ARM cores with minimum effort. This benefit reduces their long-term R&D costs and improves time-to-market.
EE Catalog: With the integration of more peripherals (touch, USB, wireless, etc.) into MCUs, how are controller vendors helping developers address new design complexities?
Duvenhage, Microchip Technology: New peripherals and application support from microcontroller vendors typically involve a combination of development kits, firmware libraries, application notes and hardware reference designs. Depending upon the needs of the application, software wizards and GUI configuration tools are sometimes developed to enable faster design cycles and easier fine tuning of the design.
Avery, Atmel: Controller vendors are enabling developers with the tools they need to ease design complexity and decrease the time-to-market for their products. Key to this is a complete, easy-to-use development platform such as the recently introduced Atmel AVR Studio 5 that supports all Atmel 8- and 32-bit microcontrollers. Developers can use one platform for writing and simulating code and directly program and debug their hardware. Also, development environments need to support a software and application framework that gives developers direct access to app notes, drivers, CODECs, math libraries and completed example projects. Of course, for more complex, time-critical designs, developers need dedicated application support from the MCU vendor.
Darrough, Zilog: Companies are now driven to keep up with design block in keeping pace with industry expectations more than ever before. The list of expected features and capabilities has grown far more complex. Many more are now offering peripheral sets that target specific applications; one-size-fits-all now has gone by the wayside. If companies don’t make significant investments then they fall behind the market’s need and cannot remain competitive.
Lees, NXP: Integration offers many design benefits and system performance improvements. Integration reduces the footprint of the design and it also reduces customers’ time-to-market because drivers are pre-characterized and ready to use. Such solutions reduce the customers’ PCB size and cost and allow designers to create a smaller formfactor for the final product or pack more functions to the system and improve performance.
EE Catalog: What are the opportunities for microcontroller vendors to continue to innovate?
Duvenhage, Microchip Technology: Microcontrollers are the original “system-on-a-chip,” so the quest to integrate the generic functionally required for new applications will continue. There are still significant opportunities with regard to mixed-signal designs, larger memory densities, user-interface designs, lowering cost and many other areas.
Avery, Atmel: Advances in process technology will continue to drive performance advances, as well as MCUs integrating more off-chip functionality. One other recent innovation is in assembly and packaging. The mobile industry is driving the need for smaller packages and solutions that are tailored for space-conscious designs.
Darrough, Zilog: Fortunately as technology expands and evolves, so do the opportunities for creativity in developing solutions. A good example is the expanding awareness and demand for energy management. There are many new products in that category, but medical, wireless, automation and consumer products are all rapidly becoming more complex, and drive innovation for better microcontrollers.
Lees, NXP: Innovations can take place in many areas, such as lower power, adding more configurable peripherals, and increased component integration. When candidates have similar or the same CPU core, customers want to choose the one with more capable and flexible peripherals that would maximize the microcontroller’s contributions to the system. Last but not the least, there is the possibility for multi-core solutions integrating the low-power 32-bit MCU with a higher performing solution. These integrated innovations address customers’ concerns in R&D design complexity, form-factor and procurement logistics.
EE Catalog: Are there new, emerging markets for 8- and 16-bit microcontrollers?
Duvenhage, Microchip Technology: 8- and 16-bit microcontrollers are leading the charge for extreme low-power consumption, both static and dynamic. This becomes critical with regard to energy efficiency and emerging applications such as personal medical devices, where the available power is very limited. On the other end, the need for intelligent pre-processing of acquired data closer to the source provides opportunities for more robust microcontrollers that operate at higher temperatures and higher voltages in these harsh environments. Additionally, cost reductions for microcontrollers are opening markets that were previously limited to discrete commodity components while bringing a higher level of sophistication to these designs.
Avery, Atmel: Yes, there are some new emerging markets with tremendous growth potential like touch, smart energy, LED lighting and MEMS to name a few. There are also traditional markets that are continually creating new design opportunities for 8/16-bit microcontrollers including wireless, industrial and automotive.
Darrough, Zilog: Certainly, although 32-bit will continue to grow for some applications, it’s basically too much for the specific need at hand. Designers are not going to put a diesel engine in their designs when what they need is a compact hybrid engine. We see more designs where three or more 8-bit MCUs are ultimately controlled by the 32-bit as they are assigned and perform the individual tasks, such as in automation applications, but it’s unlikely there’s a pressing need for everything to go to 32-bit only at this time.
Cheryl Berglund Coupé is editor of EECatalog. com. Her articles have appeared in EE Times, Electronic Business, Microsoft Embedded Review and Windows Developer’s Journal and she has developed presentations for the Embedded Systems Conference and ICSPAT. She has held a variety of production, technical marketing and writing positions within technology companies and agencies in the Northwest.