STM32F072RBT6例程，开发学习

例程：串口、中断、I2C、时钟、PWM、看门狗、定时、SD卡等 包含硬件原理图、芯片资料等，编程环境keil

/**
  ******************************************************************************
  * @file    system_stm32f0xx.c
  * @author  MCD Application Team
  * @version V1.3.1
  * @date    17-January-2014
  * @brief   CMSIS Cortex-M0 Device Peripheral Access layer System Source File.
  *          This file contains the system clock configuration for STM32F0xx devices
  *          and is generated by the clock configuration tool  
  *          STM32F0xx_Clock_Configuration_V1.0.0.xls
  *
  * 1.  This file provides two functions and one global variable to be called from 
  *     user application:
  *      - SystemInit（）: Setups the system clock （System clock source PLL Multiplier
  *                      and Divider factors AHB/APBx prescalers and Flash settings）
  *                      depending on the configuration made in the clock xls tool.
  *                      This function is called at startup just after reset and 
  *                      before branch to main program. This call is made inside
  *                      the “startup_stm32f0xx.s“ file.
  *
  *      - SystemCoreClock variable: Contains the core clock （HCLK） it can be used
  *                                  by the user application to setup the SysTick 
  *                                  timer or configure other parameters.
  *
  *      - SystemCoreClockUpdate（）: Updates the variable SystemCoreClock and must
  *                                 be called whenever the core clock is changed
  *                                 during program execution.
  *
  * 2. After each device reset the HSI （8 MHz Range） is used as system clock source.
  *    Then SystemInit（） function is called in “startup_stm32f0xx.s“ file to
  *    configure the system clock before to branch to main program.
  *
  * 3. If the system clock source selected by user fails to startup the SystemInit（）
  *    function will do nothing and HSI still used as system clock source. User can 
  *    add some code to deal with this issue inside the SetSysClock（） function.
  *
  * 4. The default value of HSE crystal is set to 8MHz refer to “HSE_VALUE“ define
  *    in “stm32f0xx.h“ file. When HSE is used as system clock source directly or
  *    through PLL and you are using different crystal you have to adapt the HSE
  *    value to your own configuration.
  *
  * 5. This file configures the system clock as follows:
  *=============================================================================
  *                         System Clock Configuration
  *=============================================================================
  *        System Clock source          | PLL（HSE）
  *-----------------------------------------------------------------------------
  *        SYSCLK                       | 48000000 Hz
  *-----------------------------------------------------------------------------
  *        HCLK                         | 48000000 Hz
  *---------------

 属性            大小     日期    时间   名称
----------- ---------  ---------- -----  ----

     文件     205424  2017-09-21 11:04  STM32F072RBT6\datasheet\STM32F072RB最小系统-原理图.PDF

     文件    1782913  2017-09-21 11:04  STM32F072RBT6\datasheet\STM32F072xx.pdf

     文件      24914  2014-01-16 23:23  STM32F072RBT6\STM32F072B-Discovery_FW_V1.0.1（官方提供）\STM32F072B-Discovery_FW_V1.0.1\STM32F072B-Discovery_FW_V1.0.1\Libraries\CMSIS\CMSIS END USER LICENCE AGREEMENT.pdf

     文件     409949  2014-01-16 23:27  STM32F072RBT6\STM32F072B-Discovery_FW_V1.0.1（官方提供）\STM32F072B-Discovery_FW_V1.0.1\STM32F072B-Discovery_FW_V1.0.1\Libraries\CMSIS\Device\Include\stm32f0xx.h

     文件       2222  2014-01-16 23:27  STM32F072RBT6\STM32F072B-Discovery_FW_V1.0.1（官方提供）\STM32F072B-Discovery_FW_V1.0.1\STM32F072B-Discovery_FW_V1.0.1\Libraries\CMSIS\Device\Include\system_stm32f0xx.h

     文件      38624  2014-01-16 23:43  STM32F072RBT6\STM32F072B-Discovery_FW_V1.0.1（官方提供）\STM32F072B-Discovery_FW_V1.0.1\STM32F072B-Discovery_FW_V1.0.1\Libraries\CMSIS\Device\Release_Notes.html

     文件      10068  2014-01-16 23:27  STM32F072RBT6\STM32F072B-Discovery_FW_V1.0.1（官方提供）\STM32F072B-Discovery_FW_V1.0.1\STM32F072B-Discovery_FW_V1.0.1\Libraries\CMSIS\Device\Source\Templates\arm\startup_stm32f030.s

     文件       9866  2014-01-16 23:27  STM32F072RBT6\STM32F072B-Discovery_FW_V1.0.1（官方提供）\STM32F072B-Discovery_FW_V1.0.1\STM32F072B-Discovery_FW_V1.0.1\Libraries\CMSIS\Device\Source\Templates\arm\startup_stm32f031.s

     文件      10703  2014-01-16 23:27  STM32F072RBT6\STM32F072B-Discovery_FW_V1.0.1（官方提供）\STM32F072B-Discovery_FW_V1.0.1\STM32F072B-Discovery_FW_V1.0.1\Libraries\CMSIS\Device\Source\Templates\arm\startup_stm32f042.s

     文件      10703  2014-01-16 23:27  STM32F072RBT6\STM32F072B-Discovery_FW_V1.0.1（官方提供）\STM32F072B-Discovery_FW_V1.0.1\STM32F072B-Discovery_FW_V1.0.1\Libraries\CMSIS\Device\Source\Templates\arm\startup_stm32f051.s

     文件      11163  2014-01-16 23:27  STM32F072RBT6\STM32F072B-Discovery_FW_V1.0.1（官方提供）\STM32F072B-Discovery_FW_V1.0.1\STM32F072B-Discovery_FW_V1.0.1\Libraries\CMSIS\Device\Source\Templates\arm\startup_stm32f072.s

     文件      10703  2014-01-16 23:27  STM32F072RBT6\STM32F072B-Discovery_FW_V1.0.1（官方提供）\STM32F072B-Discovery_FW_V1.0.1\STM32F072B-Discovery_FW_V1.0.1\Libraries\CMSIS\Device\Source\Templates\arm\startup_stm32f0xx.s

     文件       9870  2014-01-16 23:27  STM32F072RBT6\STM32F072B-Discovery_FW_V1.0.1（官方提供）\STM32F072B-Discovery_FW_V1.0.1\STM32F072B-Discovery_FW_V1.0.1\Libraries\CMSIS\Device\Source\Templates\arm\startup_stm32f0xx_ld.s

     文件       8237  2014-01-16 23:27  STM32F072RBT6\STM32F072B-Discovery_FW_V1.0.1（官方提供）\STM32F072B-Discovery_FW_V1.0.1\STM32F072B-Discovery_FW_V1.0.1\Libraries\CMSIS\Device\Source\Templates\gcc_ride7\startup_stm32f030.s

     文件       8057  2014-01-16 23:27  STM32F072RBT6\STM32F072B-Discovery_FW_V1.0.1（官方提供）\STM32F072B-Discovery_FW_V1.0.1\STM32F072B-Discovery_FW_V1.0.1\Libraries\CMSIS\Device\Source\Templates\gcc_ride7\startup_stm32f031.s

     文件       8577  2014-01-16 23:27  STM32F072RBT6\STM32F072B-Discovery_FW_V1.0.1（官方提供）\STM32F072B-Discovery_FW_V1.0.1\STM32F072B-Discovery_FW_V1.0.1\Libraries\CMSIS\Device\Source\Templates\gcc_ride7\startup_stm32f042.s

     文件       8677  2014-01-16 23:27  STM32F072RBT6\STM32F072B-Discovery_FW_V1.0.1（官方提供）\STM32F072B-Discovery_FW_V1.0.1\STM32F072B-Discovery_FW_V1.0.1\Libraries\CMSIS\Device\Source\Templates\gcc_ride7\startup_stm32f051.s

     文件       9013  2014-01-16 23:27  STM32F072RBT6\STM32F072B-Discovery_FW_V1.0.1（官方提供）\STM32F072B-Discovery_FW_V1.0.1\STM32F072B-Discovery_FW_V1.0.1\Libraries\CMSIS\Device\Source\Templates\gcc_ride7\startup_stm32f072.s

     文件       8670  2014-01-16 23:27  STM32F072RBT6\STM32F072B-Discovery_FW_V1.0.1（官方提供）\STM32F072B-Discovery_FW_V1.0.1\STM32F072B-Discovery_FW_V1.0.1\Libraries\CMSIS\Device\Source\Templates\gcc_ride7\startup_stm32f0xx.s

     文件      10333  2014-01-16 23:27  STM32F072RBT6\STM32F072B-Discovery_FW_V1.0.1（官方提供）\STM32F072B-Discovery_FW_V1.0.1\STM32F072B-Discovery_FW_V1.0.1\Libraries\CMSIS\Device\Source\Templates\iar\startup_stm32f030.s

     文件      10071  2014-01-16 23:27  STM32F072RBT6\STM32F072B-Discovery_FW_V1.0.1（官方提供）\STM32F072B-Discovery_FW_V1.0.1\STM32F072B-Discovery_FW_V1.0.1\Libraries\CMSIS\Device\Source\Templates\iar\startup_stm32f031.s

     文件      10902  2014-01-16 23:27  STM32F072RBT6\STM32F072B-Discovery_FW_V1.0.1（官方提供）\STM32F072B-Discovery_FW_V1.0.1\STM32F072B-Discovery_FW_V1.0.1\Libraries\CMSIS\Device\Source\Templates\iar\startup_stm32f042.s

     文件      11340  2014-01-16 23:27  STM32F072RBT6\STM32F072B-Discovery_FW_V1.0.1（官方提供）\STM32F072B-Discovery_FW_V1.0.1\STM32F072B-Discovery_FW_V1.0.1\Libraries\CMSIS\Device\Source\Templates\iar\startup_stm32f051.s

     文件      11687  2014-01-16 23:27  STM32F072RBT6\STM32F072B-Discovery_FW_V1.0.1（官方提供）\STM32F072B-Discovery_FW_V1.0.1\STM32F072B-Discovery_FW_V1.0.1\Libraries\CMSIS\Device\Source\Templates\iar\startup_stm32f072.s

     文件      11340  2014-01-16 23:27  STM32F072RBT6\STM32F072B-Discovery_FW_V1.0.1（官方提供）\STM32F072B-Discovery_FW_V1.0.1\STM32F072B-Discovery_FW_V1.0.1\Libraries\CMSIS\Device\Source\Templates\iar\startup_stm32f0xx.s

     文件      10074  2014-01-16 23:27  STM32F072RBT6\STM32F072B-Discovery_FW_V1.0.1（官方提供）\STM32F072B-Discovery_FW_V1.0.1\STM32F072B-Discovery_FW_V1.0.1\Libraries\CMSIS\Device\Source\Templates\iar\startup_stm32f0xx_ld.s

     文件      12651  2014-01-16 23:27  STM32F072RBT6\STM32F072B-Discovery_FW_V1.0.1（官方提供）\STM32F072B-Discovery_FW_V1.0.1\STM32F072B-Discovery_FW_V1.0.1\Libraries\CMSIS\Device\Source\Templates\system_stm32f0xx.c

     文件       7826  2014-01-16 23:27  STM32F072RBT6\STM32F072B-Discovery_FW_V1.0.1（官方提供）\STM32F072B-Discovery_FW_V1.0.1\STM32F072B-Discovery_FW_V1.0.1\Libraries\CMSIS\Device\Source\Templates\TrueSTUDIO\startup_stm32f030.s

     文件       7649  2014-01-16 23:27  STM32F072RBT6\STM32F072B-Discovery_FW_V1.0.1（官方提供）\STM32F072B-Discovery_FW_V1.0.1\STM32F072B-Discovery_FW_V1.0.1\Libraries\CMSIS\Device\Source\Templates\TrueSTUDIO\startup_stm32f031.s

     文件       8116  2014-01-16 23:27  STM32F072RBT6\STM32F072B-Discovery_FW_V1.0.1（官方提供）\STM32F072B-Discovery_FW_V1.0.1\STM32F072B-Discovery_FW_V1.0.1\Libraries\CMSIS\Device\Source\Templates\TrueSTUDIO\startup_stm32f042.s

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