Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/STMicroelectronics/STM32L15xxE/I2C1/CCR#0x0
CCR
Clock control register in Fast/Standard mode (Master mode)
Fast mode duty cycle
I2C master mode selection
https://github.com/cmsis-svd/cmsis-svd-data