With on-chip Power-On Reset, VDD monitor, Watchdog Timer, and clock oscillator, the C8051F31x  devices are truly stand-alone System-on-a-Chip solutions. The Flash memory can be reprogrammed even in-circuit, providing non-volatile data storage, and also allowing field upgrades of the 8051 firmware. User software has complete control of all peripherals, and may individually shut down any or all peripherals for power savings.

The on-chip Silicon Labs 2-Wire (C2) Development Interface allows non-intrusive (uses no on-chip resources), full speed, in-circuit debugging using the production MCU installed in the final application. This debug logic supports inspection and modification of memory and registers, setting breakpoints, single stepping, run and halt commands. All analog and digital peripherals are fully functional while debugging using C2. The two C2 interface pins can be shared with user functions, allowing in-system programming and debugging without occupying package pins.

Each device is specified for 2.7-to-3.6 V operation over the industrial temperature range (–45 to +85 °C). The Port I/O and RST pins are tolerant of input signals up to 5 V. The C8051F31x are available in 32-pin LQFP, 28-pin QFN, and 24-pin QFN packages.