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RM0351
Reset and clock control (RCC)
278
configuration register (RCC_CFGR)
.
•
LSCO
Another output (LSCO) allows a low speed clock to be output onto the external LSCO
pin:
–
LSI
–
LSE
This output remains available in Stop (Stop 0, Stop 1 and Stop 2) and Standby modes.
The selection is controlled by the LSCOSEL, and enabled with the LSCOEN in the
Backup domain control register (RCC_BDCR)
The configuration registers of the corresponding GPIO port must be programmed in
alternate function mode.
6.2.18 Internal/external
clock
measurement with TIM15/TIM16/TIM17
It is possible to indirectly measure the frequency of all on-board clock sources by mean of
the TIM15, TIM16 or TIM17 channel 1 input capture, as represented on
and
.
Figure 18. Frequency measurement with TIM15 in capture mode
The input capture channel of the Timer 15 can be a GPIO line or an internal clock of the
MCU. This selection is performed through the TI1_RMP bit in the TIM15_OR register. The
possibilities are the following ones:
•
TIM15 Channel1 is connected to the GPIO. Refer to the alternate function mapping in
the device datasheets.
•
TIM15 Channel1 is connected to the LSE.
069
7,0
7,
7,B503
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