#include "core_cm3.h"

 #include "system_stm32f10x.h"

 #include <stdint.h>

 /** @addtogroup Exported_types

   * @{

   */  

 /*!< STM32F10x Standard Peripheral Library old types (maintained for legacy purpose) */

 typedef int32_t  s32;

 typedef int16_t s16;

 typedef int8_t  s8;

 typedef const int32_t sc32;  /*!< Read Only */

 typedef const int16_t sc16;  /*!< Read Only */

 typedef const int8_t sc8;   /*!< Read Only */

 typedef __IO int32_t  vs32;

 typedef __IO int16_t  vs16;

 typedef __IO int8_t   vs8;

 typedef __I int32_t vsc32;  /*!< Read Only */

 typedef __I int16_t vsc16;  /*!< Read Only */

 typedef __I int8_t vsc8;   /*!< Read Only */

 typedef uint32_t  u32;

 typedef uint16_t u16;

 typedef uint8_t  u8;

 typedef const uint32_t uc32;  /*!< Read Only */

 typedef const uint16_t uc16;  /*!< Read Only */

 typedef const uint8_t uc8;   /*!< Read Only */

 typedef __IO uint32_t  vu32;

 typedef __IO uint16_t vu16;

 typedef __IO uint8_t  vu8;

 typedef __I uint32_t vuc32;  /*!< Read Only */

 typedef __I uint16_t vuc16;  /*!< Read Only */

 typedef __I uint8_t vuc8;   /*!< Read Only */

 typedef enum {RESET = , SET = !RESET} FlagStatus, ITStatus;

 typedef enum {DISABLE = , ENABLE = !DISABLE} FunctionalState;

 #define IS_FUNCTIONAL_STATE(STATE) (((STATE) == DISABLE) || ((STATE) == ENABLE))

 typedef enum {ERROR = , SUCCESS = !ERROR} ErrorStatus;

 /*

  * 'signed' is redundant below, except for 'signed char' and if

  * the typedef is used to declare a bitfield.

  */

     /* 7.18.1.1 */

     /* exact-width signed integer types */

 typedef   signed          char int8_t;

 typedef   signed short     int int16_t;

 typedef   signed           int int32_t;

 typedef   signed       __INT64 int64_t;

     /* exact-width unsigned integer types */

 typedef unsigned          char uint8_t;

 typedef unsigned short     int uint16_t;

 typedef unsigned           int uint32_t;

 typedef unsigned       __INT64 uint64_t;

     /* 7.18.1.2 */

     /* smallest type of at least n bits */

     /* minimum-width signed integer types */

 typedef   signed          char int_least8_t;

 typedef   signed short     int int_least16_t;

 typedef   signed           int int_least32_t;

 typedef   signed       __INT64 int_least64_t;

     /* minimum-width unsigned integer types */

 typedef unsigned          char uint_least8_t;

 typedef unsigned short     int uint_least16_t;

 typedef unsigned           int uint_least32_t;

 typedef unsigned       __INT64 uint_least64_t;

     /* 7.18.1.3 */

     /* fastest minimum-width signed integer types */

 typedef   signed           int int_fast8_t;

 typedef   signed           int int_fast16_t;

 typedef   signed           int int_fast32_t;

 typedef   signed       __INT64 int_fast64_t;

     /* fastest minimum-width unsigned integer types */

 typedef unsigned           int uint_fast8_t;

 typedef unsigned           int uint_fast16_t;

 typedef unsigned           int uint_fast32_t;

 typedef unsigned       __INT64 uint_fast64_t;

     /* 7.18.1.4 integer types capable of holding object pointers */

 #if __sizeof_ptr == 8

 typedef   signed       __INT64 intptr_t;

 typedef unsigned       __INT64 uintptr_t;

 #else

 typedef   signed           int intptr_t;

 typedef unsigned           int uintptr_t;

 #endif

     /* 7.18.1.5 greatest-width integer types */

 typedef   signed     __LONGLONG intmax_t;

 typedef unsigned     __LONGLONG uintmax_t;

• float ——4个byte，有符号型，可以表达负数/小数； Float 类型至少要能精确表示到小数点后6位。
• double——8个byte，有符号型，可以表达负数/小数；Double 类型至少要能精确到小数点后 10 位。

二、不同数据类型混合运算

在C语言中，不同类型的数据间是可以混合运算的。在进行运算时，不同类型的数据要先转换成同一类型，然后进行运算。转换的规则如下：

注意：箭头的方向只表示数据类型级别的高低，由低向高转换，这个转换过程是一步到位的。

（三）数据类型转换规则

各类数据类型的转换，分为两种方式：隐式（编译软件自动完成），显式（程序强制转换）

隐式转换规则：

字符必须先转换为整数(C语言规定字符类型数据和整型数据之间可以通用) 
   short型转换为int型(同属于整型) 
   float型数据在运算时一律转换为双精度(double)型，以提高运算精度(同属于实型) 
   赋值时，一律是右部值转换为左部类型 
[注] 
     当整型数据和双精度数据进行运算时，C先将整型数据转换成双精度型数据，再进行运算，结果为双精度类型数据 
     当字符型数据和实型数据进行运算时，C先将字符型数据转换成实型数据，然后进行计算，结果为实型数据

显式转换规则：

例：(int)(x+y);

注：强制类型转换时，得到一个所需要的中间变量，原来变量的类型未发生变化。