/**
??******************************************************************************
??*?@file????system_stm32l4xx.c
??*?@author??MCD?Application?Team
??*?@version?V1.0.1
??*?@date????16-September-2015
??*?@brief???CMSIS?Cortex-M4?Device?Peripheral?Access?layer?System?Source?File
??*
??*???This?file?provides?two?functions?and?one?global?variable?to?be?called?from
??*???user?application:
??*??????-?SystemInit（）:?This?function?is?called?at?startup?just?after?reset?and
??*??????????????????????before?branch?to?main?program.?This?call?is?made?inside
??*??????????????????????the?“startup_stm32l4xx.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.
??*
??*???After?each?device?reset?the?MSI?（4?MHz）?is?used?as?system?clock?source.
??*???Then?SystemInit（）?function?is?called?in?“startup_stm32l4xx.s“?file?to
??*???configure?the?system?clock?before?to?branch?to?main?program.
??*
??*???This?file?configures?the?system?clock?as?follows:
??*=============================================================================
??*-----------------------------------------------------------------------------
??*????????System?Clock?source????????????????????|?MSI
??*-----------------------------------------------------------------------------
??*????????SYSCLK（Hz）?????????????????????????????|?4000000
??*-----------------------------------------------------------------------------
??*????????HCLK（Hz）???????????????????????????????|?4000000
??*-----------------------------------------------------------------------------
??*????????AHB?Prescaler??????????????????????????|?1
??*-----------------------------------------------------------------------------
??*????????APB1?Prescaler?????????????????????????|?1
??*-----------------------------------------------------------------------------
??*????????APB2?Prescaler?????????????????????????|?1
??*-----------------------------------------------------------------------------
??*????????PLL_M??????????????????????????????????|?1
??*-----------------------------------------------------------------------------
??*????????PLL_N??????????????????????????????????|?8
??*-----------------------------------------------------------------------------
??*????????PLL_P??????????????????????????????????|?7
??*-----------------------------------------------------------------------------
??*????????PLL_Q??????????????????????????????????|?2
??*-----------------------------------------------------------------------------
??*????????PLL_R??????????????????????????????????|?2
?

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

?????文件?????687089??2015-10-26?23:00??Drivers\CMSIS\Device\ST\STM32L4xx\Include\stm32l471xx.h

?????文件?????757340??2015-10-26?23:00??Drivers\CMSIS\Device\ST\STM32L4xx\Include\stm32l475xx.h

?????文件?????763407??2015-10-26?23:00??Drivers\CMSIS\Device\ST\STM32L4xx\Include\stm32l476xx.h

?????文件?????767856??2015-10-26?23:00??Drivers\CMSIS\Device\ST\STM32L4xx\Include\stm32l485xx.h

?????文件?????773923??2015-10-26?23:00??Drivers\CMSIS\Device\ST\STM32L4xx\Include\stm32l486xx.h

?????文件???????6535??2015-10-26?23:00??Drivers\CMSIS\Device\ST\STM32L4xx\Include\stm32l4xx.h

?????文件???????3827??2015-10-26?23:00??Drivers\CMSIS\Device\ST\STM32L4xx\Include\system_stm32l4xx.h

?????文件??????15397??2015-10-26?23:00??Drivers\CMSIS\Device\ST\STM32L4xx\Release_Notes.html

?????文件??????20228??2015-10-26?23:00??Drivers\CMSIS\Device\ST\STM32L4xx\Source\Templates\arm\startup_stm32l471xx.s

?????文件??????20342??2015-10-26?23:00??Drivers\CMSIS\Device\ST\STM32L4xx\Source\Templates\arm\startup_stm32l475xx.s

?????文件??????20415??2015-10-26?23:00??Drivers\CMSIS\Device\ST\STM32L4xx\Source\Templates\arm\startup_stm32l476xx.s

?????文件??????20399??2015-10-26?23:00??Drivers\CMSIS\Device\ST\STM32L4xx\Source\Templates\arm\startup_stm32l485xx.s

?????文件??????20489??2015-10-26?23:00??Drivers\CMSIS\Device\ST\STM32L4xx\Source\Templates\arm\startup_stm32l486xx.s

?????文件??????14145??2015-10-26?23:00??Drivers\CMSIS\Device\ST\STM32L4xx\Source\Templates\gcc\startup_stm32l471xx.s

?????文件??????14238??2015-10-26?23:00??Drivers\CMSIS\Device\ST\STM32L4xx\Source\Templates\gcc\startup_stm32l475xx.s

?????文件??????14317??2015-10-26?23:00??Drivers\CMSIS\Device\ST\STM32L4xx\Source\Templates\gcc\startup_stm32l476xx.s

?????文件??????14321??2015-10-26?23:00??Drivers\CMSIS\Device\ST\STM32L4xx\Source\Templates\gcc\startup_stm32l485xx.s

?????文件??????14404??2015-10-26?23:00??Drivers\CMSIS\Device\ST\STM32L4xx\Source\Templates\gcc\startup_stm32l486xx.s

?????文件???????1646??2015-10-26?23:00??Drivers\CMSIS\Device\ST\STM32L4xx\Source\Templates\iar\linker\stm32l471xx_flash.icf

?????文件???????1610??2015-10-26?23:00??Drivers\CMSIS\Device\ST\STM32L4xx\Source\Templates\iar\linker\stm32l471xx_sram.icf

?????文件???????1646??2015-10-26?23:00??Drivers\CMSIS\Device\ST\STM32L4xx\Source\Templates\iar\linker\stm32l475xx_flash.icf

?????文件???????1610??2015-10-26?23:00??Drivers\CMSIS\Device\ST\STM32L4xx\Source\Templates\iar\linker\stm32l475xx_sram.icf

?????文件???????1646??2015-10-26?23:00??Drivers\CMSIS\Device\ST\STM32L4xx\Source\Templates\iar\linker\stm32l476xx_flash.icf

?????文件???????1610??2015-10-26?23:00??Drivers\CMSIS\Device\ST\STM32L4xx\Source\Templates\iar\linker\stm32l476xx_sram.icf

?????文件???????1646??2015-10-26?23:00??Drivers\CMSIS\Device\ST\STM32L4xx\Source\Templates\iar\linker\stm32l485xx_flash.icf

?????文件???????1610??2015-10-26?23:00??Drivers\CMSIS\Device\ST\STM32L4xx\Source\Templates\iar\linker\stm32l485xx_sram.icf

?????文件???????1646??2015-10-26?23:00??Drivers\CMSIS\Device\ST\STM32L4xx\Source\Templates\iar\linker\stm32l486xx_flash.icf

?????文件???????1610??2015-10-26?23:00??Drivers\CMSIS\Device\ST\STM32L4xx\Source\Templates\iar\linker\stm32l486xx_sram.icf

?????文件??????22471??2015-10-26?23:00??Drivers\CMSIS\Device\ST\STM32L4xx\Source\Templates\iar\startup_stm32l471xx.s

?????文件??????22616??2015-10-26?23:00??Drivers\CMSIS\Device\ST\STM32L4xx\Source\Templates\iar\startup_stm32l475xx.s

............此處省略79個文件信息