Reset and clock control (RCC) RM0440
328/2126 RM0440 Rev 4
Bits 17:16 I2C3SEL[1:0]: I2C3 clock source selection
These bits are set and cleared by software to select the I2C3 clock source.
00: PCLK selected as I2C3 clock
01: System clock (SYSCLK) selected as I2C3 clock
10: HSI16 clock selected as I2C3 clock
11: Reserved
Bits 15:14 I2C2SEL[1:0]: I2C2 clock source selection
These bits are set and cleared by software to select the I2C2 clock source.
00: PCLK selected as I2C2 clock
01: System clock (SYSCLK) selected as I2C2 clock
10: HSI16 clock selected as I2C2 clock
11: Reserved
Bits 13:12 I2C1SEL[1:0]: I2C1 clock source selection
These bits are set and cleared by software to select the I2C1 clock source.
00: PCLK selected as I2C1 clock
01: System clock (SYSCLK) selected as I2C1 clock
10: HSI16 clock selected as I2C1 clock
11: Reserved
Bits 11:10 LPUART1SEL[1:0]: LPUART1 clock source selection
These bits are set and cleared by software to select the LPUART1 clock source.
00: PCLK selected as LPUART1 clock
01: System clock (SYSCLK) selected as LPUART1 clock
10: HSI16 clock selected as LPUART1 clock
11: LSE clock selected as LPUART1 clock
Bits 9:8 UART5SEL[1:0]: UART5 clock source selection
These bits are set and cleared by software to select the UART5 clock source.
00: PCLK selected as UART5 clock
01: System clock (SYSCLK) selected as UART5 clock
10: HSI16 clock selected as UART5 clock
11: LSE clock selected as UART5 clock
Bits 7:6 UART4SEL[1:0]: UART4 clock source selection
This bit is set and cleared by software to select the UART4 clock source.
00: PCLK selected as UART4 clock
01: System clock (SYSCLK) selected as UART4 clock
10: HSI16 clock selected as UART4 clock
11: LSE clock selected as UART4 clock