Datasheet

DocID17659 Rev 9 41/131
STM32L151x6/8/B, STM32L152x6/8/B Pin descriptions
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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 STM32L1xxxx 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.
6. Unlike in the LQFP64 package, there is no PC3 in the TFBGA64 package. The V
REF+
functionality is provided instead.