Clock Selection
Bit7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
CLKSEL[1:0] | |||||||
Access | R/W | R/W | |||||
Reset | 0 | 0 |
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.
Value | Name | Description |
---|---|---|
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 |