Nations Technologies Inc.
Tel
:
+86-755-86309900
:
Address: Nations Tower, #109 Baoshen Road, Hi-tech Park North.
Nanshan District, Shenzhen, 518057, P.R.China
53
/
631
Clock Tree Diagram
Figure 4-2 Clock Tree
1. The maximum frequency available for the system clock is 108MHz.
2. For more details about the internal and external clock source characteristics, please refer to the "Electrical Characteristics" section in
the product datasheet.
HSE clock
The high-speed external clock signal (HSE) can be generated from the following two clock sources:
HSE external crystal/ceramic resonator
/2
/2
PLLHSEPRES
PLLSRCDIV
HSE
PLLCLK
HSI
TRNG 1M
Prescaler
/2/4/
/32
ADC 1M
Prescaler
/1/2/
/32
SYSCLK
108MHz
MAX
HCLK
ADC HCLK
prescaler
/1/2/
/32
ADC_PLLCLK
ADC_HCLK
ADC1MSEL
TRNG1MSEL
HSI
HSE
HSI
HSE
48MHz
FLASH_CLK
to Flash programming
USB_CLK
to USB interface
TRNG_CLK 1M
ADC_CLK 1M
ADC_CLK
FCLK
CPU
AHB BUS
HCLK
/8
SysTick
SAC_CLK CRC_CLK
DMA_CLK
APB1
Prescaler
/1/2/4/8/16
27MHz MAX
PCLK1 to
APB1 peripherals
54MHz MAX
PCLK2 to
APB2 peripherals
TIM 2/3/4/5/6/7/9
If(APB1 Prescaler = 1) x1
else x2
TIM2/3/4/5/6/7/9_CLK
TIM1/8_CLK
RTCSEL
RTC_CLK(to RTC)
IWDG_CLK
SYSCLK
LSI
HSE
MSI
LSE
LSI
MCO
PLLCLK
Clock Tree
MCO
OSC32_IN
OSC32_OUT
OSC_IN
OSC_OUT
Legend:
HSE = High-speed external clock signal
HSI = High-speed internal clock signal
MSI = Multi-speed internal clock signal
LSE = Low-speed external clock signal
LSI = Low-speed internal clock signal
TIMCLKSEL
RNGC_CLK
SCLKSW
CLKSSEN
HSE OSC
4~32MHz
HSI RC
16MHz
LSE OSC
32.768KHz
LSI RC
40KHz
/32
PLLMULFCT
x2,x3,...x16,
x17...x32
AHB
Prescaler
/1/2/
/512
ADC PLL
prescaler
/1/2/
/256
APB2
Prescaler
/1/2/4/8/16
TIM 1/8
If(APB2 Prescaler = 1) x1
else x2
SYSCLK
RNGC prescaler
/1/2/3/4/
/32
USB
Prescaler
/1/1.5/2/3
MSI RC
100KHz~
4MHz
MSI
/2
PLLHSIPRE
PLLSRC
LSE
HSE
SYSCLK
HSI
108MHz
MAX
LPTIMSEL
PCLK1
LSI
LSE
HSI
COMP1_OUT
COMP2_OUT
LPTIM_CLK
LPUARTSEL
PCLK1
SYSCLK
LSE
HSI
LPUART_CLK
LSECLKSSEN
PLL MCOPRES
Prescaler
1/2/3/4/.../16
ADC_HCLK
ADCPLLPRES[4]