EFM32WG Datasheet, PDF (557/834 Pages) List of Unclassifed Manufacturers – The EFM32WG Wonder Gecko is the ideal choice for demanding 8-, 16-, and 32-bit energy sensitive applications.

Figure 21.1. RTC Overview
...the world's most energy friendly microcontrollers
Peripheral bus
LFACLK_RTC
Count er (CNT)
Clear
Com pare 0
( COMP0 )
=
Com pare 1
( COMP1 )
=
RTC Cont rol and
St at us
Com pare m at ch 0
Com pare m at ch 1
21.3.1 Counter
The RTC is enabled by setting the EN bit in the RTC_CTRL register. It counts up as long as it is
enabled, and will on an overflow simply wrap around and continue counting. The RTC is cleared when
it is disabled. The timer value is both readable and writable and the RTC always starts counting from 0
when enabled. The value of the counter can be read or modified using the RTC_CNT register.
21.3.1.1 Clock Source
The RTC clock source and its prescaler value are defined in the Register Description section of the Clock
Management Unit (CMU). The clock used by the RTC has a frequency given by Equation 21.1 (p. 557) .
RTC Frequency Equation
f_RTC = f_LFACLK/2^RTC_PRESC
(21.1)
where f_LFACLK is the LFACLK frequency (32.768 kHz) and RTC_PRESC is a 4 bit value. Table 21.1 (p.
558) shows the time of overflow and resolution of the RTC at the available prescaler values.
To use this module, the LE interface clock must be enabled in CMU_HFCORECLKEN0 in addition to
the module clock
2013-05-08 - Wonder Gecko Family - d0233_Rev0.50
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