"If you're going to drive a dc brushless motor with a variable speed algorithm, then you need a microcontroller that has a specialized timer," Tyagi said. "You also need a waveform that can switch the motor on and off and vary the speed effectively."
The appliance market needs such features, Tyagi said. "If you stand and watch your washing machine for 15 minutes, you'll be amazed at how often it changes the drum speed during that amount of time. That requires a lot of computational power."
Tyagi also pointed to other potential applications where high energy efficiency requirements are becoming the norm. Inverters for solar-power applications and uninterruptible power supplies for big server farms are increasingly migrating toward more efficient software algorithms for precise control, he said.
The RX62G family offers performance features that are said to be well-suited for such applications. The new MCUs run at 100MHz, with embedded Flash memory that is said to operate at CPU speed with no wait state.
"You need some headroom to drive the complex algorithms that are used in these applications," Tyagi said. "You could put these features on a less powerful controller, but the question is whether other controllers would have the performance to drive these applications effectively."