/**
??******************************************************************************
??*?@file????system_stm32f4xx.c
??*?@author??MCD?Application?Team
??*?@version?V2.6.1
??*?@date????14-February-2017
??*?@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_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.
??*
??*
??******************************************************************************
??*?@attention
??*
??*?
©?COPYRIGHT?2017?STMicroelectronics

??*
??*?Redistribution?and?use?in?source?and?binary?forms?with?or?without?modification
??*?are?permitted?provided?that?the?following?conditions?are?met:
??*???1.?Redistributions?of?source?code?must?retain?the?above?copyright?notice
??*??????this?list?of?conditions?and?the?following?disclaimer.
??*???2.?Redistributions?in?binary?form?must?reproduce?the?above?copyright?notice
??*??????this?list?of?conditions?and?the?following?disclaimer?in?the?documentation
??*??????and/or?other?materials?provided?with?the?distribution.
??*???3.?Neither?the?name?of?STMicroelectronics?nor?the?names?of?its?contributors
??*??????may?be?used?to?endorse?or?promote?products?derived?from?this?software
??*??????without?specific?prior?written?permission.
??*
??*?THIS?SOFTWARE?IS?PROVIDED?BY?THE?COPYRIGHT?HOLDERS?AND?CONTRIBUTORS?“AS?IS“
??*?AND?ANY?EXPRESS?OR?IMPLIED?WARRANTIES?INCLUDING?BUT?NOT?LIMITED?TO?THE
??*?IMPLIED?WARRANTIES?OF?MERCHANTABILITY?AND?FITNESS?FOR?A?PARTICULAR?PURPOSE?ARE
??*?DISCLAIMED.?IN?NO?EVENT?SHALL?THE?COPYRIGHT?HOLDER?OR?CONTRIBUTORS?BE?LIABLE
??*?FOR?ANY?DIRECT?INDIRECT?INCIDENTAL?SPECIAL?EXEMPLARY?OR?CONSEQUENTIAL
??*?DAMAGES?（INCLUDING?BUT?NOT?LIMITED?TO?PROCUREMENT?OF?SUBSTITUTE?GOODS?OR
??*?SERVICES;?LOSS?OF?USE?DATA?OR?PROFITS;?OR?BUSINESS?INTERRUPTION）?HOWEVER
??*?CAUSED?AND?ON?ANY?THEORY?OF?LIABILITY?WHETHER?IN?CONTRACT?STRICT?LIABILITY
??*?OR?TORT?（INCLUDING?NEGLIGENCE?OR?OTHERWISE）?ARISING?IN?ANY?WAY?OUT?OF?THE?USE
??*?OF?THIS?SOFTWARE?EVEN?IF?ADVISED?OF?THE?POSSIBILITY?OF?SUCH?DAMAGE.
??*
??******************************************************************************
??*/

/**?@addtogroup?CMSIS
??*?@{
??*/

/**?@addtogroup?stm32f4xx_system

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----
?????目錄???????????0??2019-11-12?02:44??STM32-HC-SR04-master\
?????文件????????3719??2019-11-12?02:44??STM32-HC-SR04-master\.mxproject
?????目錄???????????0??2019-11-12?02:44??STM32-HC-SR04-master\Drivers\
?????目錄???????????0??2019-11-12?02:44??STM32-HC-SR04-master\Drivers\CMSIS\
?????目錄???????????0??2019-11-12?02:44??STM32-HC-SR04-master\Drivers\CMSIS\DSP_Lib\
?????目錄???????????0??2019-11-12?02:44??STM32-HC-SR04-master\Drivers\CMSIS\DSP_Lib\Source\
?????目錄???????????0??2019-11-12?02:44??STM32-HC-SR04-master\Drivers\CMSIS\DSP_Lib\Source\BasicMathFunctions\
?????文件????????4949??2019-11-12?02:44??STM32-HC-SR04-master\Drivers\CMSIS\DSP_Lib\Source\BasicMathFunctions\arm_abs_f32.c
?????文件????????5279??2019-11-12?02:44??STM32-HC-SR04-master\Drivers\CMSIS\DSP_Lib\Source\BasicMathFunctions\arm_abs_q15.c
?????文件????????4301??2019-11-12?02:44??STM32-HC-SR04-master\Drivers\CMSIS\DSP_Lib\Source\BasicMathFunctions\arm_abs_q31.c
?????文件????????4933??2019-11-12?02:44??STM32-HC-SR04-master\Drivers\CMSIS\DSP_Lib\Source\BasicMathFunctions\arm_abs_q7.c
?????文件????????4741??2019-11-12?02:44??STM32-HC-SR04-master\Drivers\CMSIS\DSP_Lib\Source\BasicMathFunctions\arm_add_f32.c
?????文件????????4283??2019-11-12?02:44??STM32-HC-SR04-master\Drivers\CMSIS\DSP_Lib\Source\BasicMathFunctions\arm_add_q15.c
?????文件????????4405??2019-11-12?02:44??STM32-HC-SR04-master\Drivers\CMSIS\DSP_Lib\Source\BasicMathFunctions\arm_add_q31.c
?????文件????????4092??2019-11-12?02:44??STM32-HC-SR04-master\Drivers\CMSIS\DSP_Lib\Source\BasicMathFunctions\arm_add_q7.c
?????文件????????4478??2019-11-12?02:44??STM32-HC-SR04-master\Drivers\CMSIS\DSP_Lib\Source\BasicMathFunctions\arm_dot_prod_f32.c
?????文件????????4772??2019-11-12?02:44??STM32-HC-SR04-master\Drivers\CMSIS\DSP_Lib\Source\BasicMathFunctions\arm_dot_prod_q15.c
?????文件????????4857??2019-11-12?02:44??STM32-HC-SR04-master\Drivers\CMSIS\DSP_Lib\Source\BasicMathFunctions\arm_dot_prod_q31.c
?????文件????????5249??2019-11-12?02:44??STM32-HC-SR04-master\Drivers\CMSIS\DSP_Lib\Source\BasicMathFunctions\arm_dot_prod_q7.c
?????文件????????5408??2019-11-12?02:44??STM32-HC-SR04-master\Drivers\CMSIS\DSP_Lib\Source\BasicMathFunctions\arm_mult_f32.c
?????文件????????5152??2019-11-12?02:44??STM32-HC-SR04-master\Drivers\CMSIS\DSP_Lib\Source\BasicMathFunctions\arm_mult_q15.c
?????文件????????5041??2019-11-12?02:44??STM32-HC-SR04-master\Drivers\CMSIS\DSP_Lib\Source\BasicMathFunctions\arm_mult_q31.c
?????文件????????4403??2019-11-12?02:44??STM32-HC-SR04-master\Drivers\CMSIS\DSP_Lib\Source\BasicMathFunctions\arm_mult_q7.c
?????文件????????4428??2019-11-12?02:44??STM32-HC-SR04-master\Drivers\CMSIS\DSP_Lib\Source\BasicMathFunctions\arm_negate_f32.c
?????文件????????4479??2019-11-12?02:44??STM32-HC-SR04-master\Drivers\CMSIS\DSP_Lib\Source\BasicMathFunctions\arm_negate_q15.c
?????文件????????4049??2019-11-12?02:44??STM32-HC-SR04-master\Drivers\CMSIS\DSP_Lib\Source\BasicMathFunctions\arm_negate_q31.c
?????文件????????3979??2019-11-12?02:44??STM32-HC-SR04-master\Drivers\CMSIS\DSP_Lib\Source\BasicMathFunctions\arm_negate_q7.c
?????文件????????4930??2019-11-12?02:44??STM32-HC-SR04-master\Drivers\CMSIS\DSP_Lib\Source\BasicMathFunctions\arm_offset_f32.c
?????文件????????4398??2019-11-12?02:44??STM32-HC-SR04-master\Drivers\CMSIS\DSP_Lib\Source\BasicMathFunctions\arm_offset_q15.c
?????文件????????4285??2019-11-12?02:44??STM32-HC-SR04-master\Drivers\CMSIS\DSP_Lib\Source\BasicMathFunctions\arm_offset_q31.c
?????文件????????4327??2019-11-12?02:44??STM32-HC-SR04-master\Drivers\CMSIS\DSP_Lib\Source\BasicMathFunctions\arm_offset_q7.c
............此處省略737個文件信息