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2014-07-02 - Gecko Family - d0001_Rev1.30
104
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11.5 Register Description
11.5.1 CMU_CTRL - CMU Control Register
Offset
Bit Position
0x000
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Reset
0
0x0
0x3
0
1
0x0
0x3
0
0x1
0x3
0x0
Access
RW
RW
RW
RW
RW
RW
RW
RW
RW
RW
RW
Name
Bit
Name
Reset
Access
Description
31:24
Reserved
To ensure compatibility with future devices, always write bits to 0. More information in Section 2.1 (p. 3)
23
CLKOUTSEL1
0
RW
Clock Output Select 1
Controls the clock output multiplexer. To actually output on the pin, set CLKOUT1PEN in CMU_ROUTE.
Value
Mode
Description
0
LFRCO
LFRCO (directly from oscillator).
1
LFXO
LFXO (directly from oscillator).
22:20
CLKOUTSEL0
0x0
RW
Clock Output Select 0
Controls the clock output multiplexer. To actually output on the pin, set CLKOUT0PEN in CMU_ROUTE.
Value
Mode
Description
0
HFRCO
HFRCO (directly from oscillator).
1
HFXO
HFXO (directly from oscillator).
2
HFCLK2
HFCLK/2.
3
HFCLK4
HFCLK/4.
4
HFCLK8
HFCLK/8.
5
HFCLK16
HFCLK/16.
6
ULFRCO
ULFRCO (directly from oscillator).
19:18
LFXOTIMEOUT
0x3
RW
LFXO Timeout
Configures the start-up delay for LFXO.
Value
Mode
Description
0
8CYCLES
Timeout period of 8 cycles.
1
1KCYCLES
Timeout period of 1024 cycles.
2
16KCYCLES
Timeout period of 16384 cycles.
3
32KCYCLES
Timeout period of 32768 cycles.
17
LFXOBUFCUR
0
RW
LFXO Boost Buffer Current
This value has been updated to the correct level during calibration and should not be changed.
16:14
Reserved
To ensure compatibility with future devices, always write bits to 0. More information in Section 2.1 (p. 3)
13
LFXOBOOST
1
RW
LFXO Start-up Boost Current
Adjusts start-up boost current for LFXO.
Value
Mode
Description
0
70PCENT
70 %.
1
100PCENT
100 %.
12:11
LFXOMODE
0x0
RW
LFXO Mode
Set this to configure the external source for the LFXO. The oscillator setting takes effect when 1 is written to LFXOEN in
CMU_OSCENCMD. The oscillator setting is reset to default when 1 is written to LFXODIS in CMU_OSCENCMD.
Summary of Contents for EFM32G
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