20MHz CPUXV2 core with USB 2.0
The MSP430F6631IPZR is a 16-bit MCU from the MSP430F6xx series, built around the MSP430 CPUXV2 core running at 20MHz. It integrates a full-speed USB 2.0 peripheral (device/host/OTG) alongside I²C, IrDA, LINbus, SCI, SPI, and UART/USART serial interfaces — a single-chip anchor for a mixed-signal control board that also needs to talk to a host PC over USB.
192KB Flash, 18K RAM — memory budget
Program memory is 192KB of Flash (192K x 8), with 18K x 8 of SRAM. For a typical USB data-logger application, the Flash holds the firmware stack plus a lookup table; the 18KB RAM leaves room for a 4KB USB buffer and a moderate-size circular buffer for sensor data before requiring external memory.
74 GPIO in 100-LQFP
The 100-LQFP package (14x14 mm body) brings out 74 general-purpose I/O pins. Peripheral set includes Brown-out Detect/Reset, DMA, POR, PWM, and WDT — enough to drive a small keypad, an LCD segment driver, and several PWM-controlled actuators without external port expanders.
Texas Instruments has marked the MSP430F6631IPZR as Obsolete.