Tag Archives: XMEGA AVR

Vegard Wollan on the AVR and ARM cores and peripherals

In the fifth video of the series, I asked the co-inventor of the AVR microcontroller about the progression of the peripherals in the various microcontrollers Atmel offers. Vegard shares that when they invented the first AVR products, the team was concerned with ease-of-use, a clean instruction set that would run C, instructions that ran in a single cycle, and good quality tools.

However, he was just as proud of the peripherals that they then developed for the XMEGA line of AVR 8-bit chips. There, he said the stress was still on low power, but also a set of peripherals that were high performance, robust, strong, effective, and that included analog and digital advanced peripherals. Additionally, Vegard stressed how the XMEGA event system would allow programmers to handle complex events and take action, all without waking up the CPU core in the part.


Vegard Wollan becomes animated when talking about the peripherals in AVR and ARM chips offered by Atmel.

I knew this was cool for the low-power aspect, yet Vegard reminded me that it also allows you to service an interrupt faster and more deterministically — always a good thing in embedded systems. The great news for engineers is that all the cool things Atmel figured out for the XMEGA AVR also went into to the UC3, the 32-bit AVR product lines. Then, we made sure to put these same powerful and flexible peripheral systems into our ARM core-based MCUs. In addition we would add dedicated touch I/O pins and more accurate clocks and references. You can still see the AVR DNA from back in 1990 at the Norwegian University of Science and Technology where the AVR came to life.

What I really loved about Vegard was his humility. Every time I tried to give him credit for the AVR he was sure to remind me that there was a whole team that developed it. And, when I tried to point that the AVR was RISC (reduced instruction set computer) before ARM came out, he told me that he was more proud of the peripherals in all of Atmel’s chips, rather than just the core he invented for the AVR. That’s a good thing to keep in mind.

While using any ARM core will get you the instruction set and header files and open-source tools, Atmel’s ARM chips will also get these great peripherals and the event system to tie them all together, while the CPU sleeps peacefully. A recent article helped me understand Vegard’s Norwegian modesty, but I am sure glad he and his team worked on the AVR and ARM chips.

Building a three-phase PMSM sensorless FOC with Atmel

A three-phase Permanent Magnet Synchronous Motor (PMSM) sensorless FOC (Field Oriented Control) is typically found in a number of home appliances such as washing machines, dishwashers, dryers, refrigerators, air conditioners and pumps.


Key design considerations for a three-phase PMSM sensorless FOC include power efficient and acoustically quiet motor operation to meet governmental efficiency standards, low BOM cost and a compact, scalable FOC form factor.

“And that is precisely why Atmel’s XMEGA AVR (D or E series), coupled with our AVR1636 reference design, offers developers versatile integration capabilities along with comprehensive application support – facilitating FOC implementation that allows power efficient and acoustically quiet motor control application,” an Atmel engineering rep told Bits & Pieces.

“More specifically, there are three 16-bit timer/counters with up to four output compare or input capture channels, a high-resolution extension and advanced waveform extension (AWeX), an 8-channel Event System which allows peripherals to directly send, receive and react to synchronous or asynchronous events in a short, guaranteed response time.”

Additional integrated features include a feature-rich 300KS/s 12bit ADC with programmable gain amplifier up to 64x – with temperature, supply voltage and reference inputs; EEPROM for configuration parameters storage; two USART, one SPI and one I2C Serial Interfaces for system communication.

In terms of software and application support, Atmel offers AVR1636 reference design hardware; a firmware and PC configuration utility; AVR1610 pre-certified Class B library and design guide; Atmel Studio 6; Atmel Software Framework; Atmel Gallery; and free software libraries of production-ready source code.

Interested in learning more about building a three-phase PMSM sensorless FOC with Atmel’s AVR XMEGA? Be sure to check out some of the links below.