The internal operations of the DA14580 can be divided into a number of functional blocks. The heart of the DA14580 is the control processor, an ARM CortexM0. The µCore is supported by 50 k bytes of RAM and on chip ROM to hold the operating system and protocol stack. The device also includes 32 k bytes of user programmable ROM. This programmable memory allows a low cost standalone usage model of the device where field upgradability is not required. The Bluetooth radio is the key to the DA14580’s power consumption. Developed by Renesas' experienced low power RF team the block implements all the radio, signal processing and data formatting needed by the Bluetooth Smart standard. The DA14580 includes a comprehensive set of external interfaces and ports. These include serial ports (UART, I2C and SPI), ADC, Timers, Pulse Width Modulator, rotary encoder input, keyboard scanner and up to thirty-two GPIO lines. On chip oscillators for the sleep clock (32.768 kHz) and master clock (16 MHz) are provided. Finally, the device includes comprehensive power management with both step-up and step-down DC-DC convertors giving an operating voltage range of 0.9 V to 3.5 V.