/**
??******************************************************************************
??*?@file????system_stm32f4xx.c
??*?@author??MCD?Application?Team
??*?@version?V1.0.2
??*?@date????05-March-2012
??*?@brief???CMSIS?Cortex-M4?Device?Peripheral?Access?layer?System?Source?File.
??*??????????This?file?contains?the?system?clock?configuration?for?STM32F4xx?devices
??*??????????and?is?generated?by?the?clock?configuration?tool
??*??????????stm32f4xx_Clock_Configuration_V1.0.1.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_stm32f4xx.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?（16?MHz）?is?used?as?system?clock?source.
??*????Then?SystemInit（）?function?is?called?in?“startup_stm32f4xx.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?25MHz?refer?to?“HSE_VALUE“?define
??*????in?“stm32f4xx.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:
??*=============================================================================
??*=============================================================================
??*????????Supported?STM32F4xx?device?revision????|?Rev?A
??*-----------------------------------------------------------------------------
??*????????System?Clock?source????????????????????|?PLL?（HSE）
??*-----------------------------------------------------------------------------
??*????????SYSCLK（Hz）?????????????????????????????|?168000000
??*-----

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----

?????文件????????844??2014-12-01?10:27??STM32_USB-Host-Device_Lib_V2.1.0\Project\429_HID.build_log.htm

?????文件????????947??2014-12-01?12:55??STM32_USB-Host-Device_Lib_V2.1.0\Project\objects\429_HID.build_log.htm

?????文件????????479??2014-12-01?10:29??STM32_USB-Host-Device_Lib_V2.1.0\Project\objects\429_HID.sct

?????文件???????2991??2014-12-01?10:37??STM32_USB-Host-Device_Lib_V2.1.0\Project\objects\usbd_usr.d

?????文件?????466336??2014-12-01?10:37??STM32_USB-Host-Device_Lib_V2.1.0\Project\objects\usbd_usr.o

?????文件???????2701??2014-12-01?10:37??STM32_USB-Host-Device_Lib_V2.1.0\Project\objects\usb_core.d

?????文件?????478508??2014-12-01?10:37??STM32_USB-Host-Device_Lib_V2.1.0\Project\objects\usb_core.o

?????文件???????2719??2014-12-01?10:37??STM32_USB-Host-Device_Lib_V2.1.0\Project\objects\usb_dcd.d

?????文件?????465452??2014-12-01?10:37??STM32_USB-Host-Device_Lib_V2.1.0\Project\objects\usb_dcd.o

?????文件???????2895??2014-12-01?10:37??STM32_USB-Host-Device_Lib_V2.1.0\Project\objects\usb_dcd_int.d

?????文件?????469100??2014-12-01?10:37??STM32_USB-Host-Device_Lib_V2.1.0\Project\objects\usb_dcd_int.o

?????文件???????3190??2014-12-01?10:37??STM32_USB-Host-Device_Lib_V2.1.0\Project\objects\usbd_core.d

?????文件?????474644??2014-12-01?10:37??STM32_USB-Host-Device_Lib_V2.1.0\Project\objects\usbd_core.o

?????文件???????3374??2014-12-01?10:37??STM32_USB-Host-Device_Lib_V2.1.0\Project\objects\usbd_hid_core.d

?????文件?????471668??2014-12-01?10:37??STM32_USB-Host-Device_Lib_V2.1.0\Project\objects\usbd_hid_core.o

?????文件???????3041??2014-12-01?10:37??STM32_USB-Host-Device_Lib_V2.1.0\Project\objects\usbd_ioreq.d

?????文件?????466372??2014-12-01?10:37??STM32_USB-Host-Device_Lib_V2.1.0\Project\objects\usbd_ioreq.o

?????文件???????3058??2014-12-01?10:37??STM32_USB-Host-Device_Lib_V2.1.0\Project\objects\usbd_req.d

?????文件?????475844??2014-12-01?10:37??STM32_USB-Host-Device_Lib_V2.1.0\Project\objects\usbd_req.o

?????文件???????2327??2014-12-01?10:37??STM32_USB-Host-Device_Lib_V2.1.0\Project\objects\misc.d

?????文件?????432168??2014-12-01?10:37??STM32_USB-Host-Device_Lib_V2.1.0\Project\objects\misc.o

?????文件???????2678??2014-12-01?10:37??STM32_USB-Host-Device_Lib_V2.1.0\Project\objects\stm32f4xx_rcc.d

?????文件?????447164??2014-12-01?10:37??STM32_USB-Host-Device_Lib_V2.1.0\Project\objects\stm32f4xx_rcc.o

?????文件???????2717??2014-12-01?10:37??STM32_USB-Host-Device_Lib_V2.1.0\Project\objects\stm32f4xx_gpio.d

?????文件?????394644??2014-12-01?10:37??STM32_USB-Host-Device_Lib_V2.1.0\Project\objects\429_HID.axf

?????文件?????395298??2014-12-01?10:37??STM32_USB-Host-Device_Lib_V2.1.0\Project\objects\system_stm32f4xx.crf

?????文件?????436264??2014-12-01?10:37??STM32_USB-Host-Device_Lib_V2.1.0\Project\objects\stm32f4xx_gpio.o

?????文件?????????61??2014-12-01?10:37??STM32_USB-Host-Device_Lib_V2.1.0\Project\objects\startup_stm32f4xx.d

?????文件?????????19??2014-12-01?10:38??STM32_USB-Host-Device_Lib_V2.1.0\Project\objects\ExtDll.iex

?????文件?????394201??2014-12-01?10:37??STM32_USB-Host-Device_Lib_V2.1.0\Project\objects\misc.crf

............此處省略157個文件信息