Datasheet

Pin descriptions STM32L100C6, STM32L100R8/RB
34/102 DocID024295 Rev 1
4. The PC14 and PC15 I/Os are only configured as OSC32_IN/OSC32_OUT when the LSE oscillator is on (by setting the
LSEON bit in the RCC_CSR register). The LSE oscillator pins OSC32_IN/OSC32_OUT can be used as general-purpose
PC14/PC15 I/Os, respectively, when the LSE oscillator is off ( after reset, the LSE oscillator is off ). The LSE has priority
over the GPIO function. For more details, refer to Using the OSC32_IN/OSC32_OUT pins as GPIO PC14/PC15 port pins
section in the STM32Lxx reference manual (RM0038).
5. The PH0 and PH1 I/Os are only configured as OSC_IN/OSC_OUT when the HSE oscillator is on ( by setting the HSEON
bit in the RCC_CR register). The HSE oscillator pins OSC_IN/OSC_OUT can be used as general-purpose PH0/PH1 I/Os,
respectively, when the HSE oscillator is off (after reset, the HSE oscillator is off ). The HSE has priority over the GPIO
function.