Datasheet

STM32F313xx Functional overview
Doc ID 023636 Rev 1 13/58
Figure 2. Clock tree
/32
4-32 MHz
HSE OSC
OSC_IN
OSC_OUT
OSC32_IN
OSC32_OUT
8 MHz
HSI RC
to IWDG
PLL
x2,x3,..
x16
PLLMUL
MCO
Main clock
output
AHB
/2
PLLCLK
HSI
HSE
APB1
prescaler
/1,2,4,8,16
HCLK
PLLCLK
to AHB bus, core,
memory and DMA
LSE
LSI
HSI
HSI
HSE
to RTC
PLLSRC
SW
MCO
/8
SYSCLK
RTCCLK
RTCSEL[1:0]
IWWDGCLK
SYSCLK
to TIM 2,3,4,6,7
If (APB1 prescaler
=1) x1 else x2
FLITFCLK
to Flash programming interface
LSI
to I2Cx (x = 1,2)
to USARTx (x = 2..5)
LSE
HSI
SYSCLK
/2
PCLK1
SYSCLK
HSI
PCLK1
MS30366V1
to I2Sx (x = 2,3)
to cortex System timer
FHCLK Cortex free
running clock
to APB1 peripherals
AHB
prescaler
/1,2,..512
CSS
/2,/3,...
/16
LSE OSC
32.768kHz
LSI RC
40kHz
APB2
prescaler
/1,2,4,8,16
to TIM 15,16,17
If (APB2 prescaler
=1) x1 else x2
to USART1
LSE
HSI
SYSCLK
PCLK2
PCLK2
to APB2 peripherals
TIM1/8
ADC
Prescaler
/1,2,4
to ADCxy
(xy = 12, 34)
ADC
Prescaler
/1,2,4,6,8,10,12,16,
32,64,128,256
I2SSRC
SYSCLK
Ext. clock
I2S_CKIN
x2