/**
??******************************************************************************
??*?@file????system_stm32l1xx.c
??*?@author??MCD?Application?Team
??*?@version?V1.3.3
??*?@date????20-April-2015
??*?@brief???CMSIS?Cortex-M3?Device?Peripheral?Access?layer?System?Source?File.
??*??????????This?file?contains?the?system?clock?configuration?for?STM32L1xx?Ultra
??*??????????Low?Power?devices?and?is?generated?by?the?clock?configuration
??*??????????tool?“STM32L1xx_Clock_Configuration_V1.1.0.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_stm32l1xx_xx.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?MSI?（2.1?MHz?Range）?is?used?as?system?clock?source.
??*????Then?SystemInit（）?function?is?called?in?“startup_stm32l1xx_xx.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?MSI?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?“stm32l1xx.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???????????????????????|?32000000?Hz
??*---------------------------------

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----
?????目錄???????????0??2018-08-20?09:45??NB_stm32l151\
?????目錄???????????0??2018-08-20?09:45??NB_stm32l151\CMSIS\
?????目錄???????????0??2018-08-20?09:45??NB_stm32l151\CMSIS\Include\
?????文件????????4676??2015-04-20?21:15??NB_stm32l151\CMSIS\Include\arm_common_tables.h
?????文件????????3666??2015-04-20?21:15??NB_stm32l151\CMSIS\Include\arm_const_structs.h
?????文件??????242444??2015-04-20?21:15??NB_stm32l151\CMSIS\Include\arm_math.h
?????文件???????33042??2015-04-20?21:15??NB_stm32l151\CMSIS\Include\core_cm0.h
?????文件???????40429??2015-04-20?21:15??NB_stm32l151\CMSIS\Include\core_cm0plus.h
?????文件???????99832??2015-04-20?21:15??NB_stm32l151\CMSIS\Include\core_cm3.h
?????文件??????109142??2015-04-20?21:15??NB_stm32l151\CMSIS\Include\core_cm4.h
?????文件???????22735??2015-04-20?21:15??NB_stm32l151\CMSIS\Include\core_cm4_simd.h
?????文件???????17146??2015-04-20?21:15??NB_stm32l151\CMSIS\Include\core_cmFunc.h
?????文件???????20513??2015-04-20?21:15??NB_stm32l151\CMSIS\Include\core_cmInstr.h
?????文件???????41744??2015-04-20?21:15??NB_stm32l151\CMSIS\Include\core_sc000.h
?????文件???????98211??2015-04-20?21:15??NB_stm32l151\CMSIS\Include\core_sc300.h
?????文件??????505206??2015-04-21?01:56??NB_stm32l151\CMSIS\Include\stm32l1xx.h
?????文件????????2220??2015-04-21?01:56??NB_stm32l151\CMSIS\Include\system_stm32l1xx.h
?????文件???????20175??2015-04-21?01:56??NB_stm32l151\CMSIS\system_stm32l1xx.c
?????目錄???????????0??2018-08-20?09:45??NB_stm32l151\Libraries\
?????目錄???????????0??2018-08-20?09:45??NB_stm32l151\Libraries\inc\
?????文件????????9173??2015-04-21?01:56??NB_stm32l151\Libraries\inc\misc.h
?????文件???????28932??2015-04-21?01:56??NB_stm32l151\Libraries\inc\stm32l1xx_adc.h
?????文件????????9391??2015-04-21?01:56??NB_stm32l151\Libraries\inc\stm32l1xx_aes.h
?????文件????????7062??2015-04-21?01:56??NB_stm32l151\Libraries\inc\stm32l1xx_comp.h
?????文件????????2414??2015-04-21?01:56??NB_stm32l151\Libraries\inc\stm32l1xx_crc.h
?????文件???????14712??2015-04-21?01:56??NB_stm32l151\Libraries\inc\stm32l1xx_dac.h
?????文件????????3823??2015-04-21?01:56??NB_stm32l151\Libraries\inc\stm32l1xx_dbgmcu.h
?????文件???????21338??2015-04-21?01:56??NB_stm32l151\Libraries\inc\stm32l1xx_dma.h
?????文件????????8724??2015-04-21?01:56??NB_stm32l151\Libraries\inc\stm32l1xx_exti.h
?????文件???????28215??2015-04-21?01:56??NB_stm32l151\Libraries\inc\stm32l1xx_flash.h
?????文件???????16537??2015-04-21?01:56??NB_stm32l151\Libraries\inc\stm32l1xx_fsmc.h
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