The nRF54LM20B SoC can use the optional 32.768 kHz crystal X2 for higher accuracy and lower average power consumption.
On the nRF54LM20 DK, P1.20 and P1.21 are used for the 32.768 kHz crystal by default and are not available as GPIOs on the headers.
By cutting solder bridges SB1 and SB2 and soldering SB3 and SB4, crystal X2 is disconnected and GPIOs P1.20 and P1.21 are connected to the header for general use.
Figure 1. 32.768 kHz crystal X1 and SB1–SB4
Figure 2. 32.768 kHz crystal and SB1 and SB2
