March 6, 2012 -- Whether they're used in smart meters, wireless sensor nodes, or mobile health-monitoring products, microcontrollers (MCUs) are at the heart of almost every real-time application that demands prompt, predictable response to real-world events. In many of these applications the MCU relies on sophisticated sleep-mode techniques that suspend most or all of its operations to minimize energy consumption, allowing it to run for years or even decades on limited energy sources.

These real-time low-energy environments pose special challenges for the designer and programmer because the same sleep states that reduce an MCU's energy consumption often also reduce its ability to quickly respond to an event.

By Anders Guldahl. (Guldahl is an application engineer at Energy Micro.)