The CC2640 is a Bluetooth Smart wireless microcontroller that provides a complete solution on a single chip. It has three cores which can be separately powered and controlled. The application processor is an ARM Cortex M3. It runs the Bluetooth Smart Profiles along with any user defined functionality. 20 kB of RAM and up to 128 kB of Flash is available, although, as shown later, the Bluetooth low energy Stack also runs on this processor and occupies part of this memory. An ARM Cortex M0 runs the Bluetooth low energy Radio Firmware from ROM and ensures that all timing regarding the RF protocol is handled properly. The M0 is not available for user programming. The RF Core is controlled by the ARM Cortex M0 and enables up to +5 dBM output power and -97 dBM sensitivity for Bluetooth Smart communication in the 2.4 GHz frequency band. The third and final core on the CC2640 is the Sensor Controller Engine (SCE). This small, RISC CPU has been designed to off-load the M3. When the rest of the system is in standby mode, the SCE can run small algoritms and/or communicate with sensors in a low power manner. It can wake up on interrupt and perform simple processing. For example, calculating average sensor or threshhold values, before waking up the M3 for further processing and transmission. The CC2640 includes a wide set of peripherals for serial communication as well as general purpose IO and timers. There is a separate set of peripherals for the SCE.