The MSP430 CPU16 core runs at 16 MHz, which is the top speed for the MSP430F2xx family. The 512 x 8 RAM (512 bytes) and 4 KB Flash program memory (4K x 8 plus 256 bytes of information memory) are the limiting resources.
The MSP430F2122TRTVR includes a UART/USART module, which directly answers the question of serial communication capability — yes, it has a UART. The connectivity set also covers I²C, SPI, IrDA, and LINbus, so it can talk to common sensors, displays, and transceivers without external protocol translation. On the analog side, an 8-channel 10-bit ADC is built in, adequate for reading potentiometers, thermistors, or current-sense resistors at moderate resolution. The brown-out detect and POR circuits are integrated, which saves an external supervisor IC in cost-sensitive designs.