16-bit MSP430 core at 16 MHz
The MSP430G2221IPW14 is a 16-bit MCU from the MSP430G2xx series, built around the MSP430 CPU16 core clocked at 16 MHz. This speed rating sets the instruction throughput ceiling — at 16 MHz the core executes up to 16 MIPS, enough for sensor polling, serial protocol handling, and low-duty-cycle control loops.
Memory budget and peripheral set
On-chip memory is 2 KB of Flash (2K x 8) and 128 bytes of RAM (128 x 8). The Flash holds firmware and constant data; the 128-byte RAM limits runtime variables to small buffers — a typical application might use 64 bytes for a sensor readout and 32 bytes for a communication frame, leaving 32 bytes for the stack. I2C and SPI connectivity are available via the serial interface module, and 10 general-purpose I/O pins are brought out to the 14-TSSOP package.
On-chip supervisory and timing peripherals
Integrated peripherals include brown-out detect and power-on reset (POR), a watchdog timer (WDT), and a PWM module. The brown-out detect holds the core in reset when Vcc drops below the threshold, preventing code corruption during power transients. The WDT provides a last-resort recovery from firmware hangs — a common requirement in unattended sensor nodes.
Active lifecycle and sourcing posture
The part is ROHS3 compliant.