Reset and clock control (RCC)
RM0365
141/1080
DocID025202 Rev 7
9.4.8
APB1 peripheral clock enable register (RCC_APB1ENR)
Address: 0x1C
Reset value: 0x0000 0000
Access: word, half-word and byte access
No wait state, except if the access occurs while an access to a peripheral on APB1 domain
is on going. In this case, wait states are inserted until this access to APB1 peripheral is
finished.
Note:
When the peripheral clock is not active, the peripheral register values may not be readable
by software and the returned value is always 0x0.
Bit 15
SPI4EN
: SPI4 clock enable (STM32F302xD/E only)
Set and cleared by software.
0: SPI4 clock disabled
1: SPI4 clock enabled
Bit 14
USART1EN:
USART1 clock enable
Set and cleared by software.
0: USART1 clock disabled
1: USART1 clock enabled
Bit 13 Reserved, must be kept at reset value.
Bit 12
SPI1EN:
SPI1 clock enable (STM32F302xB/C devices only)
Set and cleared by software.
0: SPI1 clock disabled
1: SPI1 clock enabled
Bit 11
TIM1EN:
TIM1 timer clock enable
Set and cleared by software.
0: TIM1 timer clock disabled
1: TIM1 timer clock enabled
Bits 10:1 Reserved, must be kept at reset value.
Bit 0
SYSCFGEN:
SYSCFG clock enable
Set and cleared by software.
0: SYSCFG clock disabled
1: SYSCFG clock enabled
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
Res
I2C3
EN
DAC1
EN
PWR
EN
Res
Res
CAN
EN
Res
USB
EN
I2C2
EN
I2C1
EN
UART5
EN
UART4
EN
USART3
EN
USART2
EN
Res
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
SPI3
EN
SPI2
EN
Res
Res
WWD
GEN
Res
Res
Res
Res
Res
Res
TIM6EN
Res
TIM4EN TIM3EN
TIM2
EN
rw
rw
rw
rw
rw
rw
rw