34.4.2 32.768 kHz Crystal Oscillator

By default, the 32.768 kHz oscillator is enabled. To use this oscillator, the XIN32 and XOUT32 pins must be connected to a 32.768 kHz crystal or to a ceramic resonator. Refer to the section “Electrical Characteristics” for appropriate loading capacitors selection on XIN32 and XOUT32.

To select the 32.768 kHz crystal oscillator as the source of TD_SLCK, SCKC_CR.TD_OSCSEL must be set to 1. This results in a sequence which first configures the PIO lines multiplexed with XIN32 and XOUT32 and driven by the crystal oscillator, and then enables the 32.768 kHz crystal oscillator. The switch of TD_SLCK source is glitch-free.