ST STM32F205 series Reference Manual page 116

Reset and clock control (RCC)
Bit 25 CAN1EN: CAN 1 clock enable
Set and cleared by software.
0: CAN 1 clock disabled
1: CAN 1 clock enabled
Bit 24 Reserved, always read as 0.
Bit 23 I2C3EN: I2C3 clock enable
Set and cleared by software.
0: I2C3 clock disabled
1: I2C3 clock enabled
Bit 22 I2C2EN: I2C2 clock enable
Set and cleared by software.
0: I2C2 clock disabled
1: I2C2 clock enabled
Bit 21 I2C1EN: I2C1 clock enable
Set and cleared by software.
0: I2C1 clock disabled
1: I2C1 clock enabled
Bit 20 UART5EN: UART5 clock enable
Set and cleared by software.
0: UART5 clock disabled
1: UART5 clock enabled
Bit 19 UART4EN: UART4 clock enable
Set and cleared by software.
0: UART4 clock disabled
1: UART4 clock enabled
Bit 18 USART3EN: USART3 clock enable
Set and cleared by software.
0: USART3 clock disabled
1: USART3 clock enabled
Bit 17 USART2EN: USART 2 clock enable
Set and cleared by software.
0: USART2 clock disabled
1: USART2 clock enabled
Bit 16 Reserved, always read as 0.
Bit 15 SPI3EN: SPI3 clock enable
Set and cleared by software.
0: SPI3 clock disabled
1: SPI3 clock enabled
Bit 14 SPI2EN: SPI2 clock enable
Set and cleared by software.
0: SPI2 clock disabled
1: SPI2 clock enabled
Bits 13:12 Reserved, always read as 0.
116/1378 RM0033 Rev 8
RM0033