An IEEE 802.15.4 compliant single chip combines an ARM® Cortex®-M0+ based 32-bit microcontroller and best-in-class 2.4GHz RF transceiver. It offers an excellent RF performance, with a link budget of 103dBm while consuming 50% less active current than existing offerings. The device features IEEE 802.15.4 MAC hardware accelerators and automatic transmission modes, wake-on-radio, offers twelve-channel direct memory access (DMA) controller, up to four configurable SERCOM modules for I2C, SPI and USART and a 128-bit AES crypto engine. The device features further blocks like a Peripheral Touch Controller (PTC), Full-Speed USB Device and embedded Host and hardware components to support RF distance measurements. To complement that set the SAM R21 also supports external power amplifiers and antenna diversity.