Clock Selection

Name:
CLKSEL
Offset:
0x07
Reset:
0x00
Access:
-
Bit76543210
CLKSEL[1:0]
AccessR/WR/W
Reset00

Bits 1:0 – CLKSEL[1:0]: Clock Select

Clock Select

Writing these bits select 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.

ValueNameDescription
0x0 INT32K 32.768 kHz from OSCULP32K
0x1 INT1K 1.024 kHz from OSCULP32K
0x2 TOSC32K 32.768 kHz from XOSC32K or external clock from TOSC1
0x3 EXTCLK External clock from EXTCLK pin