The Medium-Frequency Internal Oscillator (MFINTOSC) generates two constant clock outputs (500 kHz and 31.25 kHz). The MFINTOSC clock signals are created from the HFINTOSC using dynamic divider logic, which provides constant MFINTOSC clock rates regardless of selected HFINTOSC frequency.

The MFINTOSC cannot be used as the system clock, but can be used as a clock source for certain peripherals, such as a Timer.