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NUC126
Aug. 08, 2018
Page
170
of 943
Rev 1.03
NUC12
6 S
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CA
L R
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NCE
MA
NUA
L
XT1_OUT
External 4~24
MHz Crystal
(HXT)
HXTEN (CLK_PWRCTL[0])
XT1_IN
Internal
22.1184 MHz
Oscillator
(HIRC)
HIRCEN (CLK_PWRCTL[2])
0
1
PLL
PLLSRC (CLK_PLLCTL[19])
PLL FOUT
X32_OUT
External 32.768
kHz Crystal
(LXT)
LXT
LXTEN (CLK_PWRCTL[1])
X32_IN
Internal10 KHz
Oscillator
(LIRC)
LIRCEN(CLK_PWRCTL[3])
HXT
HIRC
LIRC
Internal 48 MHz
Oscillator
(HIRC48)
LIRCEN(CLK_PWRCTL[13])
HIRC48
Note:
Before clock switching, both the pre-selected and newly selected clock source must be turned on and stable.
Figure 6.3-1 Clock Generator Block Diagram