Embedded Systems Academy

I was visiting Embedded World this week and in regards to microcontrollers the trend towards 32bit continues. When it comes to marketing presence at a trade show, obviously less than 32bit where not “it” this year. Not only chip manufacturers, but also most of the development tools primarily focused on 32bit solutions. And the next impression one gets walking the aisles: ARM processors are the first choice in this arena, with a focus on the Cortex-M generation. At this year’s Embedded World, no other microcontroller architecture had a marketing presence anywhere near that of ARM.

After the ARM7 and ARM9 generation it is now the ARM Cortex-M processors that are going broad market, more and more chip manufacturers offer and promote derivatives of this architecture. One of the leading “embracers” of the Cortex-Mx is NXP. On the lowest end of this family NXP offers Cortex-M0 derivatives which are aimed at replacing 8 and 16bit microcontrollers and are best suited for lowest power applications. The Cortex-M3 devices are considered mid range and on the high end is the Cortex-M4 offering DSP extensions. Note that the Cortex-M4 was just recently announced and it will take a while until implementations become widely available.

As a tutor conducting various ARM trainings and being involved in tests, benchmarks and reports I am always amazed about how this industry works when promoting performance differences between microcontrollers. Looking at ARM7, ARM9 and Cortex-M variants they indeed have a different performance at the same clock rate, but none of these differences come even close to a factor of two.

In our report Performance Considerations for ARM processor based developments (available at www.esacademystore.eu) we outline where the really big traps and gaps are when trying to boost real-world performance, and it’s not the architecture sub-species. We can show that single decisions that engineers make when developing an embedded application can impact the performance by a factor of ten or more. Selecting a specific ARM processor architecture versus another family pales by comparison.

Of course, there are always some applications where exactly that difference is the one needed to make it work. But for the most part, the majority of embedded applications  do not have a very specific performance need and any ARM based microcontroller will do the job and more. Unless, of course, one makes too many bad choices in designing the application. Even the best processor performance can be nullified by poor software!

So even if ARM processors are now “everywhere”, for developers of embedded systems the selection criteria is the same as always: good development tools, right peripheral mix, availability, pricing, trusted partners – your priorities may vary…

Whenever a new microcontroller generation comes out, developers and engineers look out for evaluation boards. In order to be able to test the microcontroller, it needs to be mounted on a PCB that has the required glue logic, power circuitry and connectors. For generations, these test boards were mostly “bare-naked” – without housing and only featuring components needed to test the microcontroller in certain types of applications. Over the last years more “attractive” variations of such boards have come to market, for example some looking like a custom USB stick.

Last year, Raisonance released products following a slightly different concept they named Primers, and the Primer2 won an EETimes product of the year 2009 award. These boards feature a complete housing, making them more attractive for various prototype developments. Through staging several design contests, many applications have been implemented and are now shared on the product’s web page. Applications include an alcohol meter, a CAN monitor, a GPS displaying OpenStreetMap data, various games and many more.

At this years Embedded World, Raisonance introduced the next generation, the Open4 Primer. The most obvious changes are that the new housing is a bit bigger and gives a much sturdier impression. It offers more room for custom extensions as the space for daughter boards is bigger as well. The color display with touchscreen is about twice the size of the previous version, providing more screen space for visualizations. All primers use microcontrollers from ST, the latest Open4 has an STM32E which is a Cortex-M3 derivative.

There is hardly a more fun platform to evaluate a Cortex-M3 microcontroller.

A few years back, Al Gore was speaking at the Embedded Systems Conference. His key note also included the call upon us engineers to do more to ensure that embedded systems use less power. With the billions of microcontrollers out there, all the milliwatts that we can potentially save in each one do add-up. Although many microcontroller manufacturers already offer multiple power saving options on their devices, it is not always easy to get exact values. Any change in clock rate, also on any of the peripherals, immediately has an affect on the overall power consumption. But how much do we really save by reducing the clock to a communication peripheral?

This year, one of the Embedded Awards given out every year at the Embedded World is for a product that helps engineers with measuring the power consumption of their system dynamically. The PowerScale by Hitex not only allows measuring a system’s current power consumption – it makes that information available via an API so that debuggers can include the information into the trace recording or other displays.

This allows engineers to easily determine which code areas have an impact on the overall power consumption. The power-saving effect of reducing clock rates or disabling unused peripherals becomes immediately visibile.

Various adapter probes including a USB and Power-over-Ethernet Probe are available to allow for an easy connection of the up to four channels to the target hardware.

The Production System version can now be installed by an Administrator User and then used by a Limited User, ideal for production line use. The Limited User can access all the functionality of the application (with the exception of Ethernet bootloader support) and they cannot uninstall it.

This release also contains some minor improvements for the P89(L)V51Rx2 and LPC1751 devices. Get it now from http://www.flashmagictool.com.