11.3 Functional Description
An overview of the high frequency portion of the CMU is shown in
Figure 11.1 CMU Overview - High Frequency Portion on page 280
.
An overview of the low frequency portion is shown in
Figure 11.2 CMU Overview - Low Frequency Portion on page 281
. These figures
show the CMU for the largest device in the EFR32 family. Refer to the Configuration Summary in the device data sheet to see which
core, radio, and peripheral modules, and therefore clock connections, are present in a specific device.
HFRCO
HFXO
Timeout
HFCLK
clock
switch
CMU_HFPRESC.PRESC
HFSRCCLK
CLKIN0
prescaler
CMU_HFCLKSEL.HF
LFXO
LFRCO
Timeout
Timeout
CMU_HFPERCLKEN0.USARTn
HFPERCLK
USARTn
CMU_HFPERCLKEN0.TIMERn
HFPERCLK
TIMERn
Clock
Gate
Clock
Gate
HFPERCLK
CMU_HFPERPRESC.PRESC
prescaler
CMU_CTRL.HFPERCLKEN
HFCORECLK
CORTEX
EM0
HFCORECLK
CMU_HFCOREPRESC.PRESC
AUXCLK
CMU_DBGCLKSEL.DBG
HFBUSCLK
DMEM
CMU_HFBUSCLKEN0.GPIO
HFBUSCLK
GPIO
HFBUSCLK
BUSMATRIX
50% duty
prescaler
HFEXPCLK
CMU_HFEXPPRESC.PRESC
HFBUSCLK
LDMA
CMU_HFBUSCLKEN0.LDMA
DBGCLK
AUX
HFRCO
CMU_ADCCTRL.ADCnCLKINV
CMU_ADCCTRL.ADCnCLKSEL
ADC_CLK
ADCCLKMODE
Availability of oscillators and clocks in Energy Modes:
· Available in EM0/EM1
· Available in EM0/EM1/EM2
· Available in EM0/EM1/EM2/EM3
· Available in EM0/EM1/EM2/EM3/EM4H
· Available in EM0/EM1/EM2/EM4H/EM4S
· Available in EM0/EM1/EM2/EM3/EM4H/EM4S
prescaler
Clock
Gate
Clock
Gate
Clock
Gate
HFBUSCLK
LE
CMU_HFBUSCLKEN0.LE
Clock
Gate
Debug Trace
clock
switch
xor
ADC
HFPERCLK
ADCn
HFSRCCLK
LFRCO
LFXO
CLKIN0
HFRCO
HFXO
HFCLK
LESENSE
(High frequency timing)
AUXCLK
AUXCLK
AUXCLK
HFRCODIV2
CLKOUTn
CMU_CTRL.CLKOUTSELn
HFRCO
HFXO
50% duty
/2
HFXO
Radio Transceiver
CMU_HFRADIOCLKEN0.SYNTH
HFRADIOCLK
SYNTH
CMU_HFRADIOCLKEN0.MODEM
HFRADIOCLK
MODEM
Clock
Gate
Clock
Gate
HFRADIOCLK
CMU_HFRADIOPRESC.PRESC
prescaler
CMU_CTRL.HFRADIOCLKEN
HFXO
Figure 11.1. CMU Overview - High Frequency Portion
Reference Manual
CMU - Clock Management Unit
silabs.com
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