Clock Selection

Name:
CLKSEL
Offset:
0x07
Reset:
0x00
Access:
-
Bit76543210
CLKSEL[1:0]
AccessRRRRRRR/WR/W
Reset00000000

Bits 1:0 – CLKSEL[1:0]: Clock Select

Clock Select

Writing these bits selects the source for the RTC clock (CLK_RTC).

When configuring the RTC to use either XOSC32K or the external clock on TOSC1, XOSC32K needs to be enabled and the Source Select bit (SEL) and Run Standby bit (RUNSTDBY) in the XOSC32K Control A register of the Clock Controller (CLKCTRL.XOSC32KCTRLA) must be configured accordingly.

ValueDescription
0x0 32KHz from OSCULP32K
0x1 1KHz from OSCULP32K
0x2 32.768kHz from XOSC32K
0x3 External clock from TOSC1 pin