22.7.5 Clock Selection Control

Table 22-6. Register Bit Attribute Legend
SymbolDescriptionSymbolDescriptionSymbolDescription
RReadable bitHCCleared by Hardware(Grey cell)Unimplemented
WWritable bitHSSet by HardwareXBit is unknown at Reset
KWrite to clearSSoftware settable bit
Name: CLKSELCTRL
Offset: 0x10
Reset: 0x00000000
Property: RW

Bit 3130292827262524 
          
Access  
Reset  
Bit 2322212019181716 
          
Access  
Reset  
Bit 15141312111098 
          
Access  
Reset  
Bit 76543210 
   HSMSEL[1:0]  RTCSEL[1:0] 
Access RWRWRWRW 
Reset 0000 

Bits 5:4 – HSMSEL[1:0] HSM Clock Selection

ValueNameDescription
0x0ULP32K32.768kHz from 32kHz internal ULP oscillator
0x2XOSC32K32.768kHz from 32.768kHz external crystal oscillator

Bits 1:0 – RTCSEL[1:0] RTC Clock Selection

These bits select the RTC clock source.

ValueNameDescription
0x0ULP32K32 kHz from 32 kHz internal ULP oscillator
0x1ULP1K1 kHz from 32 kHz internal ULP oscillator
0x2XOSC32K32.768 kHz from 32 kHz external crystal oscillator
0x3XOSC1K1.024 kHz from 32 kHz external oscillator
ValueNameDescription
0x0ULP32K32.768kHz from 32kHz internal ULP oscillator
0x1ULP1K1.024kHz from 32kHz internal ULP oscillator
0x2XOSC32K32.768kHz from 32.768kHz external crystal oscillator
0x3XOSC1K1.024kHz from 32.768kHz internal oscillator