With on-chip power-on reset, voltage supply monitor, watchdog timer, and clock oscillator, the EFM8BB51 devices are truly standalone system-on-a-chip solutions. The flash memory is reprogrammable in-circuit, providing non-volatile data storage and allowing field upgrades of the firmware. The on-chip debugging interface (C2) 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, and run and halt commands. All analog and digital peripherals are fully functional while debugging. Each device is specified for 1.8 to 5.5 V. Devices are offered in 20-pin TSSOP and 20-pin QFN packages. All package options are lead-free and RoHS compliant.