This document describes the features and characteristics of the MSP430x20x1, MSP430x20x2, and MSP430x20x3 mixed signal microcontrollers, including low supply voltage range, ultralow power consumption, multiple power-saving modes, fast wake-up from standby mode, 16-bit RISC architecture, clock module configurations, timer, comparator, analog-to-digital converter, universal serial interface, brownout detector, and on-chip emulation logic.