Elettronica Plus

Cost-sensitive applications benefit from leading edge microcontrollersERT

5.6 billion US Dollars in 2013 is the revenue number for 4/8-bit microcontrollers. That prediction by market researchers at IHS means that the low-end segment accounts for 31% of the worldwide microcontroller market. Most of the devices in this segment are based on quite old processor core architectures, peripherals and also manufacturing technologies.

There are many commonly accepted reasons for this.
1. If computing performance requirements are low, there is not a huge pressure to upgrade to a higher performance processor.
2. If flash sizes of microcontrollers are small, technology shrinks do not make a lot of sense.
3. If hardware developers don’t see the need for powerful digital signal processing peripherals, you can keep them simple.
You can probably state a few more reasons. And there also is a sort of myth in the semiconductor industry: business economics dictate that low-end microcontrollers are best produced in an old, depreciated technology.

We think it’s time to re-visit this myth. To understand why, let’s first have a look at some of the important applications of low-end microcontrollers.

Start with low-end electric motors, which are used in huge quantities in washing machines, dishwashers, fans, heating pumps etc. Microcontrollers control the power circuitry, and system designers historically strive to use the lowest possible cost solution for the job. With increased pressure to save electric energy, despite the cost pressure this segment gets more and more important because the saving potential is typically above 50%.

In addition to the energy saving topics the requirements for better user experience, like less noise and improved human machine interfaces, are increasing. Yet another accelerating trend is regulatory pressure to improve safety which requires redundancy on the microcontroller but also the software running on the microcontroller. To address those challenges microcontrollers with more processing power, better peripherals and also more flash memory are needed.

In LED lighting, which is an emerging application segment for low-end microcontrollers, there are two market drivers that must be addressed. First, new peripherals are needed to control the LED drivers and to assure flicker-free dimming and brightness control. As this is directly linked to the end user experience, it is important for the wide acceptance of LED lighting. Additionally, microcontrollers for LED lighting open the possibility to connect multiple LED fixtures via a network protocol like DALI, DMX or KNX. This requires microcontrollers capable in terms of processing performance and memory range to support enhanced connectivity.

Those trends are just two examples that illustrate how energy efficiency, user experience, legal requirements and new technologies make the traditional concept of a low-end microcontroller obsolete. But still, the price target for these types of systems mean that BOM cost remains a key factor. And there also remains the need for simple microcontrollers which just evaluate some analog signals to enable simple control or communication.

Even in the simplest applications there is a new trend. While one would wish that almost every engineer leaving college should be able to program the microcontroller, nowadays the number of engineers who are interested in 8-bit microcontroller programming is very limited. The goal then is to develop the software in a high-level approach, but still be able to run the software on a low-cost microcontroller. In other words, the optimum low-end microcontroller family now must offer both innovation and cost efficiency.

The XMC1000 of Infineon is the first low-end microcontroller family manufactured using a 65nm embedded flash manufacturing process on 300mm wafers. Besides the use of the 32-bit ARM Cortex-M0 processor, adopting a leading-edge production approach allowed to integrate peripherals used in the higher-end XMC4000 microcontroller family; e.g. PWM units enabling asymmetrical PWM wave forms, automatic dead-time insertion and much more, and ADC features (12-bit resolution, 2 sample and hold stages, 1.88 mega samples/second etc.). XMC1000 offers peripherals for cost-sensitive electric motor control systems which are also used to control industrial servo-drives.

In certain family members there are also innovative peripherals for autonomous LED lighting control, touch sensing, and LED matrix control. Most important, this microcontroller family is fully integrated in Infineon’s DAVE integrated development platform. This is a free, unlimited, Eclipse based development environment which introduces component based programming to the low-end microcontroller world. In a graphical IDE one can configure and combine software components, known as “DAVE Apps”. DAVE assigns these components to the microcontroller hardware resources and automatically generates code that can be compiled and debugged in the integrated free tool-chain.

In talking about software we see a new trend related to protecting software IP and enabling new business models. The idea is simple: link the software to a limited number of chips. XMC1000 is the first low-end microcontroller to enable this by integrating 128 bit AES as a security mechanism. Protecting software IP will become more and more important, since as hardware component cost continues to decrease the value of the software running on the “cheap” hardware increases. Protecting software IP also is of special interest for software design houses. If the software can be linked to a certain number of chips, copying software does not make so much sense anymore and royalty-based business models become much more attractive for them.

We are convinced that a transition from 8-bit MCUs to inexpensive, innovative, 32-bit microcontrollers is needed to address the rising demands for energy efficiency, safety, security, connectivity and usability in so-called low-end applications. This requires leading edge hardware and software technology. With XMC1000 and DAVE Infineon takes a large step in this direction.