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基于STM32F10时钟系统MCU的开发及配置

来源：电子发烧友

2018-10-22

类别：技术信息

215

拍明

原标题：基于STM32时钟系统的开发及配置

一、背景

最近做个项目,需要使用STM32,还是以前一样的观点,时钟就是MCU心脏,供血即时钟频率输出,想要弄明白一个MCU,时钟是一个非常好的切入点。言归正传,网上已经有太多大神详述过STM32的详细配置方法了,在此就简单介绍下STM32时钟系统,以及如何配置做个简单记录,方便以后的快速开发。

二、正文

废话不多说,上一张STM32F10xx的时钟树图:

基于STM32F10时钟系统的开发及配置.png

由图可知,STM32F10XX有两级时钟

第一级时钟

* 高速内部时钟(HSI)

* 锁相环时钟(PLLCLK)

* 高速外部时钟(HSE)

第二级时钟

* 低速内部时钟(LSI)

* 低速外部时钟(LSE)

又由图可知,

* HSE由外部晶振从“OSC_OUT”,“OSC_IN”两脚输入提供。

* LSE由外部晶振从“OSC32_OUT”,“OSC32_IN”两脚输入提供。

* HSI由8MHZ高速内部RC震荡电路提供。

* LSI由40kHZ低速内部RC震荡电路提供。

STM32F10XX还可通过MCO脚向外提供时钟输出。时钟来源有PLLCLK/HSI/HSE/SYSCLK,由MCO选择器来选择。

研究过时钟来源,再来研究时钟的去向,MCU自身要能正常运作,即需要一个时钟,这个时钟既是系统时钟(SYSCLK),而基本上所有外设的时钟均来自于这个系统时钟(SYSCLk)。然后由系统时钟对外提供各种外设时钟。详见图。

当然,也有例外,USB时钟必须为48MHZ,这里的USB时钟(USBCLK)由PLLCLK直接提供,RTC时钟(RTCCLK)也不是来源于系统时钟(SYSCLK),详见图。

时钟结构大体也就如此,不再深究,网上有许多更加深入的讲解,接下来说说如何去配置。用代码来说明问题:

先贴文件“system_stm32f10x.c”,此文件即库文件。里面有一个很重要的函数“SystemInit()”

解析过STM32启动代码的朋友都应该知道,这个函数跑在进入main函数之前,里面做的事情即是配置系统时钟。代码如下:

voidSystemInit(void){/*ResettheRCCclockconfigurationtothedefaultresetstate(fordebugpurpose)*//*SetHSIONbit

STM32F10主控芯片大全：

型号	Description
STM32F103VB	Mainstream Performance line, ARM Cortex-M3 MCU with 128 Kbytes Flash, 72 MHz CPU, motor control, USB and CAN
STM32F103VE	Mainstream Performance line, ARM Cortex-M3 MCU with 512 Kbytes Flash, 72 MHz CPU, motor control, USB and CAN
STM32F103R6	Mainstream Performance line, ARM Cortex-M3 MCU with 32 Kbytes Clash, 72 MHz CPU, motor control, USB and CAN
STM32F103ZE	Mainstream Performance line, ARM Cortex-M3 MCU with 512 Kbytes Flash, 72 MHz CPU, motor control, USB and CAN
STM32F103ZG	Mainstream Performance line, ARM Cortex-M3 MCU with 1 Mbyte Flash, 72 MHz CPU, motor control, USB and CAN
STM32F103CB	Mainstream Performance line, ARM Cortex-M3 MCU with 128 Kbytes Flash, 72 MHz CPU, motor control, USB and CAN
STM32F103R8	Mainstream Performance line, ARM Cortex-M3 MCU with 64 Kbytes Flash, 72 MHz CPU, motor control, USB and CAN
STM32F100C8	Mainstream Value line, ARM Cortex-M3 MCU with 64 Kbytes Flash, 24 MHz CPU, motor control and CEC functions
STM32F100R8	Mainstream Value line, ARM Cortex-M3 MCU with 64 Kbytes Flash, 24 MHz CPU, motor control and CEC functions
STM32F103VC	Mainstream Performance line, ARM Cortex-M3 MCU with 256 Kbytes Flash, 72 MHz CPU, motor control, USB and CAN
STM32F103VG	Mainstream Performance line, ARM Cortex-M3 MCU with 1 Mbyte Flash, 72 MHz CPU, motor control, USB and CAN
STM32F105VC	Mainstream Connectivity line, ARM Cortex-M3 MCU with 256 Kbytes Flash, 72 MHz CPU, CAN, USB 2.0 OTG
STM32F100RB	Mainstream Value line, ARM Cortex-M3 MCU with 128 Kbytes Flash, 24 MHz CPU, motor control and CEC functions
STM32F100VC	Mainstream value line, ARM Cortex-M3 MCU with 256 Kbytes Flash, 24 MHz CPU, motor control and CEC functions
STM32F103C6	Mainstream Performance line, ARM Cortex-M3 MCU with 32 Kbytes Flash, 72 MHz CPU, motor control, USB and CAN
STM32F103RB	Mainstream Performance line, ARM Cortex-M3 MCU with 128 Kbytes Flash, 72 MHz CPU, motor control, USB and CAN
STM32F103VD	Mainstream Performance line, ARM Cortex-M3 MCU with 384 Kbytes Flash, 72 MHz CPU, motor control, USB and CAN
STM32F103ZC	Mainstream Performance line, ARM Cortex-M3 MCU with 256 Kbytes Flash, 72 MHz CPU, motor control, USB and CAN
STM32F103ZD	Mainstream Performance line, ARM Cortex-M3 MCU with 384 Kbytes Flash, 72 MHz CPU, motor control, USB and CAN
STM32F103ZF	Mainstream Performance line, ARM Cortex-M3 MCU with 768 Kbytes Flash, 72 MHz CPU, motor control, USB and CAN

STM32F105RC	Mainstream Connectivity line, ARM Cortex-M3 MCU with 256 Kbytes Flash, 72 MHz CPU, CAN, USB 2.0 OTG
STM32F100CB	Mainstream Value line, ARM Cortex-M3 MCU with 128 Kbytes Flash, 24 MHz CPU, motor control and CEC functions
STM32F100R6	Mainstream Value line, ARM Cortex-M3 MCU with 32 Kbytes Flash, 24 MHz CPU, motor control and CEC functions
STM32F100RD	Mainstream Value line, ARM Cortex-M3 MCU with 384 Kbytes Flash, 24 MHz CPU, motor control and CEC functions
STM32F100RE	Mainstream Value line, ARM Cortex-M3 MCU with 512 Kbytes, 24 MHz CPU, motor control and CEC functions
STM32F100VD	Mainstream Value line, ARM Cortex-M3 MCU with 384 Kbytes Flash, 24 MHz CPU, motor control and CEC functions
STM32F100VE	Mainstream Value line, ARM Cortex-M3 MCU with 512 Kbytes Flash, 24 MHz CPU, motor control and CEC functions
STM32F101C8	Mainstream Access line, ARM Cortex-M3 MCU with 64 Kbytes Flash, 36 MHz CPU
STM32F101CB	Mainstream Access line, ARM Cortex-M3 MCU with 128 Kbytes Flash, 36 MHz CPU
STM32F101R6	Mainstream Access line, ARM Cortex-M3 MCU with 32 Kbytes Flash, 36 MHz CPU
STM32F103C8	Mainstream Performance line, ARM Cortex-M3 MCU with 64 Kbytes Flash, 72 MHz CPU, motor control, USB and CAN
STM32F103R4	Mainstream Performance line, ARM Cortex-M3 MCU with 16 Kbytes Flash, 72 MHz CPU, motor control, USB and CAN
STM32F103RC	Mainstream Performance line, ARM Cortex-M3 MCU with 256 Kbytes Flash, 72 MHz CPU, motor control, USB and CAN
STM32F103RE	Mainstream Performance line, ARM Cortex-M3 MCU with 512 Kbytes Flash, 72 MHz CPU, motor control, USB and CAN
STM32F103RF	Mainstream Performance line, ARM Cortex-M3 MCU with 768 Kbytes Flash, 72 MHz CPU, motor control, USB and CAN
STM32F103RG	Mainstream Performance line, ARM Cortex-M3 MCU with 1 Mbyte Flash, 72 MHz CPU, motor control, USB and CAN
STM32F103T8	Mainstream Performance line, ARM Cortex-M3 MCU with 64 Kbytes Flash, 72 MHz CPU, motor control, USB and CAN
STM32F103V8	Mainstream Performance line, ARM Cortex-M3 MCU with 64 Kbytes Flash, 72 MHz CPU, motor control, USB and CAN
STM32F105V8	Mainstream Connectivity line, ARM Cortex-M3 MCU with 64 Kbytes Flash, 72 MHz CPU, CAN, USB 2.0 OTG
STM32F105VB	Mainstream Connectivity line, ARM Cortex-M3 MCU with 128 Kbytes Flash,72 MHz CPU, CAN, USB 2.0 OTG

STM32F107VC	Mainstream Connectivity line, ARM Cortex-M3 MCU with 256 Kbytes Flash, 72 MHz CPU, Ethernet MAC, CAN and USB 2.0 OTG
STM32F100C4	Mainstream Value line, ARM Cortex-M3 MCU with 16 Kbytes Flash, 24 MHz CPU, motor control and CEC functions
STM32F100C6	Mainstream Value line, ARM Cortex-M3 MCU with 32 Kbytes Flash, 24 MHz CPU, motor control and CEC functions
STM32F100R4	Mainstream Value line, ARM Cortex-M3 MCU with 16 Kbytes Flash, 24 MHz CPU, motor control and CEC functions
STM32F100V8	Mainstream Value line, ARM Cortex-M3 MCU with 64 Kbytes Flash, 24 MHz CPU, motor control and CEC functions
STM32F100VB	Mainstream Value line, ARM Cortex-M3 MCU with 128 Kbytes Flash, 24 MHz CPU, motor control and CEC functions
STM32F100ZE	Mainstream Value line, ARM Cortex-M3 MCU with 512 Kbytes Flash, 24 MHz CPU, motor control and CEC functions
STM32F101C6	Mainstream Access line, ARM Cortex-M3 MCU with 32 Kbytes Flash, 36 MHz CPU
STM32F101RB	Mainstream Access line, ARM Cortex-M3 MCU with 128 Kbytes Flash, 36 MHz CPU
STM32F101RC	Mainstream Access line, ARM Cortex-M3 MCU with 256 Kbytes Flash, 36 MHz CPU
STM32F101T6	Mainstream Access line, ARM Cortex-M3 MCU with 32 Kbytes Flash, 36 MHz CPU
STM32F102C6	Mainstream USB Access line, ARM Cortex-M3 MCU with 32 Kbytes Flash, 48 MHz CPU, USB FS
STM32F103RD	Mainstream Performance line, ARM Cortex-M3 MCU with 384 Kbytes Flash, 72 MHz CPU, motor control, USB and CAN
STM32F103T6	Mainstream Performance line, ARM Cortex-M3 MCU with 32 Kbytes Flash, 72 MHz CPU, motor control, USB and CAN
STM32F103TB	Mainstream Performance line, ARM Cortex-M3 MCU with 128 Kbytes Flash, 72 MHz CPU, motor control, USB and CAN
STM32F103VF	Mainstream Performance line, ARM Cortex-M3 MCU with 768 Kbytes Flash, 72MHz CPU, motor control, USB and CAN
STM32F105R8	Mainstream Connectivity line, ARM Cortex-M3 with 64 Kbytes Flash, 72 MHz CPU, CAN, USB 2.0 OTG
STM32F105RB	Mainstream Connectivity line, ARM Cortex-M3 MCU with 128 Kbytes Flash, 72 MHz CPU, CAN, USB 2.0 OTG
STM32F107RB	Mainstream Connectivity line, ARM Cortex-M3 MCU with 128 Kbytes Flash, 72 MHz CPU, Ethernet MAC, CAN and USB 2.0 OTG
STM32F107RC	Mainstream Connectivity line, ARM Cortex-M3 MCU with 256 Kbytes Flash, 72 MHz CPU, Ethernet MAC, CAN and USB 2.0 OTG

STM32F107VB	Mainstream Connectivity line, ARM Cortex-M3 MCU with 128 Kbytes Flash, 72 MHz CPU, Ethernet MAC, CAN and USB 2.0 OTG
STM32F100RC	Mainstream Value line, ARM Cortex-M3 MCU with 256 Kbytes Flash, 24 MHz CPU, motor control and CEC functions
STM32F100ZD	Mainstream Value line, ARM Cortex-M3 MCU with 384 Kbytes Flash, 24 MHz CPU, motor control and CEC functions
STM32F101R8	Mainstream Access line, ARM Cortex-M3 MCU with 64 Kbytes Flash, 36 MHz CPU
STM32F101RD	Mainstream Access line, ARM Cortex-M3 MCU with 384 Kbytes Flash, 36 MHz CPU
STM32F101RE	Mainstream Access line, ARM Cortex-M3 MCU with 512 Kbytes Flash, 36 MHz CPU
STM32F101RG	Mainstream Access line, ARM Cortex-M3 MCU with 1 Mbyte Flash, 36 MHz CPU
STM32F101T4	Mainstream Access line, ARM Cortex-M3 MCU with 16 Kbytes Flash, 36 MHz CPU
STM32F101T8	Mainstream Access line, ARM Cortex-M3 MCU with 64 Kbytes Flash, 36 MHz CPU
STM32F101TB	Mainstream Access line, ARM Cortex-M3 MCU with 128 Kbytes Flash, 36 MHz CPU
STM32F101V8	Mainstream Access line, ARM Cortex-M3 MCU with 64 Kbytes Flash, 36 MHZ CPU
STM32F101VB	Mainstream Access line, ARM Cortex-M3 MCU with 128 Kbytes Flash, 36 MHz CPU
STM32F101VC	Mainstream Access line, ARM Cortex-M3 MCU with 256 Kbytes Flash, 36 MHz CPU
STM32F101VD	Mainstream Access line, ARM Cortex-M3 MCU with 384 Kbytes Flash, 36 MHz CPU
STM32F101VE	Mainstream Access line, ARM Cortex-M3 MCU with 512 Kbytes Flash, 36 MHz CPU
STM32F102C4	Mainstream USB Access line, ARM Cortex-M3 MCU with 16 Kbytes Flash, 48 MHz CPU, USB FS
STM32F102C8	Mainstream USB Access line, ARM Cortex-M3 MCU with 64 Kbytes Flash, 48 MHz CPU, USB FS
STM32F102CB	Mainstream USB Access line, ARM Cortex-M3 MCU with 128 Kbytes Flash, 48 MHz CPU, USB FS
STM32F102RB	Mainstream USB Access line, ARM Cortex-M3 MCU with 128 Kbytes Flash, 48 MHz CPU, USB FS
STM32F103C4	Mainstream Performance line, ARM Cortex-M3 MCU with 16 Kbytes Flash, 72 MHz CPU, motor control, USB and CAN

STM32F103T4	Mainstream Performance line, ARM Cortex-M3 MCU with 16 Kbytes Flash, 72 MHz CPU, motor control, USB and CAN
STM32F101VF	Mainstream Access line, ARM Cortex-M3 MCU with 768 Kbytes Flash, 36 MHz CPU
STM32F100ZC	Mainstream Value line, ARM Cortex-M3 MCU with 256 Kbytes Flash, 24 MHz CPU, motor control and CEC functions
STM32F101C4	Mainstream Access line, ARM Cortex-M3 MCU with 16 Kbytes Flash, 36 MHz CPU
STM32F101R4	Mainstream Access line, ARM Cortex-M3 MCU with 16 Kbytes Flash, 36 MHz CPU
STM32F101RF	Mainstream Access line, ARM Cortex-M3 MCU with 768 Kbytes Flash, 36 MHz CPU
STM32F101VG	Mainstream Access line, ARM Cortex-M3 MCU with 1 Mbyte Flash, 36 MHz CPU
STM32F101ZC	Mainstream Access line, ARM Cortex-M3 MCU with 256 Kbytes Flash, 36 MHz CPU
STM32F101ZD	Mainstream Access line, ARM Cortex-M3 MCU with 384 Kbytes Flash, 36 MHz CPU
STM32F101ZE	Mainstream Access line, ARM Cortex-M3 MCU with 512 Kbytes Flash, 36 MHz CPU
STM32F101ZF	Mainstream Access line, ARM Cortex-M3 MCU with 768 Kbytes Flash, 36 MHz CPU
STM32F101ZG	Mainstream Access line, ARM Cortex-M3 MCU with 1 Mbyte Flash, 36 MHz CPU
STM32F102R4	Mainstream USB Access line, ARM Cortex-M3 MCU with 16 Kbytes Flash, 48 MHz CPU, USB, FS
STM32F102R6	Mainstream USB Access line, ARM Cortex-M3 MCU with 32 Kbytes Flash, 48 MHz CPU, USB FS
STM32F102R8	Mainstream USB Access line, ARM Cortex-M3 MCU with 64 Kbytes Flash, 48 MHz CPU, USB FS