"The 64 MHz crystal oscillator (HFXO) is controlled by a 32 MHz external crystal"- How it works ?

[Artak]

In the nRF52 datasheets there is a statement: "The 64 MHz crystal oscillator (HFXO) is controlled by a 32 MHz external crystal"

Is the crystal somehow oscillating at 2nd harmonic ? is there a frequency doubler?

How much is the oscillation frequency at the XC2 output ?

[RK]

The crystal is oscillating at 32MHz. The frequency is doubled internally.