Low-, medium- and high-density reset and clock control (RCC)
RM0008
1.
2.
if the APB prescaler is 1, the timer clock frequencies are set to the same frequency as
that of the APB domain to which the timers are connected.
otherwise, they are set to twice (×2) the frequency of the APB domain to which the
timers are connected.
FCLK acts as Cortex?-M3 free running clock. For more details refer to the ARM Cortex?-
M3 Technical Reference Manual.
6.2.1
HSE clock
The high speed external clock signal (HSE) can be generated from two possible clock
sources:
HSE external crystal/ceramic resonator
HSE user external clock
The resonator and the load capacitors have to be placed as close as possible to the
oscillator pins in order to minimize output distortion and startup stabilization time. The
loading capacitance values must be adjusted according to the selected oscillator.
Figure 9.
HSE/ LSE clock sources
Clock source
Hardware configuration
OSC_OUT
External clock
(HiZ)
External
source
OSC_IN OSC_OUT
Crystal/Ceramic
resonators
C L1
Load
C L2
capacitors
External source (HSE bypass)
In this mode, an external clock source must be provided. It can have a frequency of up to 25
MHz. You select this mode by setting the HSEBYP and HSEON bits in the Clock control
register (RCC_CR) . The external clock signal (square, sinus or triangle) with ~50% duty
cycle has to drive the OSC_IN pin while the OSC_OUT pin should be left hi-Z. See Figure 9 .
78/995
Doc ID 13902 Rev 9
相关PDF资料
MCBTMPM330 BOARD EVAL TOSHIBA TMPM330 SER
MCIMX25WPDKJ KIT DEVELOPMENT WINCE IMX25
MCIMX53-START-R KIT DEVELOPMENT I.MX53
MCM69C432TQ20 IC CAM 1MB 50MHZ 100LQFP
MCP1401T-E/OT IC MOSFET DRVR INV 500MA SOT23-5
MCP1403T-E/MF IC MOSFET DRIVER 4.5A DUAL 8DFN
MCP1406-E/SN IC MOSFET DVR 6A 8SOIC
MCP14628T-E/MF IC MOSFET DVR 2A SYNC BUCK 8-DFN
相关代理商/技术参数
MCBSTM32EXLU 功能描述:开发板和工具包 - ARM EVAL BOARD + ULINK2 FOR STM32F103ZG RoHS:否 制造商:Arduino 产品:Development Boards 工具用于评估:ATSAM3X8EA-AU 核心:ARM Cortex M3 接口类型:DAC, ICSP, JTAG, UART, USB 工作电源电压:3.3 V
MCBSTM32EXLU-ED 制造商:ARM Ltd 功能描述:KEIL STM STM32EXL EVAL BOARD
MCBSTM32EXLUME 功能描述:开发板和工具包 - ARM EVAL BOARD + ULINKME FOR STM32F103ZG RoHS:否 制造商:Arduino 产品:Development Boards 工具用于评估:ATSAM3X8EA-AU 核心:ARM Cortex M3 接口类型:DAC, ICSP, JTAG, UART, USB 工作电源电压:3.3 V
MCBSTM32F200 功能描述:开发板和工具包 - ARM EVAL BOARD FOR STM STM32F207IG RoHS:否 制造商:Arduino 产品:Development Boards 工具用于评估:ATSAM3X8EA-AU 核心:ARM Cortex M3 接口类型:DAC, ICSP, JTAG, UART, USB 工作电源电压:3.3 V
MCBSTM32F200U 功能描述:开发板和工具包 - ARM EVAL BOARD FOR STM STM32F207IG + ULINK2 RoHS:否 制造商:Arduino 产品:Development Boards 工具用于评估:ATSAM3X8EA-AU 核心:ARM Cortex M3 接口类型:DAC, ICSP, JTAG, UART, USB 工作电源电压:3.3 V
MCBSTM32F200UME 功能描述:开发板和工具包 - ARM EVAL BOARD FOR STM STM32F207IG ULINK-ME RoHS:否 制造商:Arduino 产品:Development Boards 工具用于评估:ATSAM3X8EA-AU 核心:ARM Cortex M3 接口类型:DAC, ICSP, JTAG, UART, USB 工作电源电压:3.3 V
MCBSTM32F200UME-ED 制造商:ARM Ltd 功能描述:KEIL STM32F207IG EVAL BOARD
MCBSTM32F400 功能描述:开发板和工具包 - ARM EVAL BOARD FOR STM STM32F407IG RoHS:否 制造商:Arduino 产品:Development Boards 工具用于评估:ATSAM3X8EA-AU 核心:ARM Cortex M3 接口类型:DAC, ICSP, JTAG, UART, USB 工作电源电压:3.3 V