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2014-07-02 - Tiny Gecko Family - d0034_Rev1.20
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11.3.4 Output Clock on a Pin
It is possible to configure the CMU to output clocks on two pins. This clock selection is done using
CLKOUTSEL0 and CLKOUTSEL1 fields in CMU_CTRL. The output pins must be configured in the
CMU_ROUTE register.
• LFRCO, LFXO, HFCLK or the qualified clock from any of the oscillators can be output on one pin
(CMU_OUT1). A qualified clock will not have any glitches or skewed duty-cycle during startup. For
LFXO and HFXO you need to configure LFXOTIMEOUT and HFXOTIMEOUT in CMU_CTRL correctly
to guarantee a qualified clock.
• HFRCO, HFXO, HFCLK/2, HFCLK/4, HFCLK/8, HFCLK/16, ULFRCO or AUXHFRCO can be output
on another pin (CMU_OUT0)
Note that HFXO and HFRCO clock outputs to pin can be unstable after startup and should not be output
on a pin before HFXORDY/HFRCORDY is set high in CMU_STATUS.
11.3.5 Protection
It is possible to lock the control- and command registers to prevent unintended software writes to critical
clock settings. This is controlled by the CMU_LOCK register.
Summary of Contents for EFM32TG
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