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SIM_COPC[COPCLKSEL]
COP clock
Bus clock
LPO
OSCERCLK
MCGIRCLK
00
01
10
11
Figure 5-2. COP clock generation
5.7.3 RTC clocking
The RTC module can be clocked as shown in the following figure.
NOTE
The chosen clock must remain enabled if the RTC is to
continue operating in all required low-power modes.
SIM_SOPT1[OSC32KSEL]
OSC32KCLK
RTC_CLKIN
LPO
ERCLK32K
(to RTC)
00
11
10
Figure 5-3. RTC clock generation
5.7.4 RTC_CLKOUT and CLKOUT32K clocking
When the RTC is enabled and the port control module selects the RTC_CLKOUT
function, the RTC_CLKOUT signal, controlled from SIM_SOPT2[RTCCLKOUTSEL],
outputs a 1 Hz or 32 kHz output derived from RTC oscillator as shown below and can be
configured to drive to external pins via pin control configuration for the associated pin. It
is also possible to drive CLKOUT32K on the same pins as controlled by
Chapter 5 Clock Distribution
KL27 Sub-Family Reference Manual , Rev. 5, 01/2016
Freescale Semiconductor, Inc.
73