The Specified Frequency Internal Oscillator (SFINTOSC) generates a 1 MHz output clock. The SFINTOSC clock signal is created from the HFINTOSC using dynamic divider logic, which provides a constant SFINTOSC clock rate regardless of the selected HFINTOSC frequency.
The SFINTOSC cannot be used as the system clock, but may be selected as a clock source for certain peripherals, such as a Timer.