stm32变量的定义

一、最近在玩stm32，用库（V3.5.0）开发，被 stm32的变量定义搞的晕头转向，决心将其弄清楚。

在 stdint.h 文件里，我们可以清楚的看到：

typedef   signed          char int8_t;

typedef   signed short     int int16_t;

typedef   signed           int int32_t;

typedef   signed       __int64 int64_t;

typedef unsigned          char uint8_t;

typedef unsigned short     int uint16_t;

typedef unsigned           int uint32_t;

typedef unsigned       __int64 uint64_t;

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;

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;

typedef   signed           int int_fast8_t;

typedef   signed           int int_fast16_t;

typedef   signed           int int_fast32_t;

typedef   signed       __int64 int_fast64_t;

typedef unsigned           int uint_fast8_t;

typedef unsigned           int uint_fast16_t;

typedef unsigned           int uint_fast32_t;

typedef unsigned       __int64 uint_fast64_t;

typedef   signed           int intptr_t;

typedef unsigned           int uintptr_t;

typedef   signed       __int64 intmax_t;

typedef unsigned       __int64 uintmax_t;

在百度百科中，我们可以看到 stdint.h 的作用：

二、在 core_cm3.h 文件里，有如下定义：

 #ifdef __cplusplus

  #define     __I     volatile      

#else

  #define     __I     volatile const    

#endif

#define     __O     volatile    

#define     __IO    volatile    

CMSIS IO类型限定词

表格摘自 http://forum.eepw.com.cn/thread/215752/1

其中，volatile 的作用： 作为指令关键字，确保本条指令不会因编译器的优化而省略，且要求每次直接读值.

而 const 是一个C语言的关键字，它限定一个变量不允许被改变。

三、在 stm32f10x.h 文件里，有如下定义：

typedef int32_t  s32;

typedef int16_t s16;

typedef int8_t  s8;

typedef const int32_t sc32;  

typedef const int16_t sc16;  

typedef const int8_t sc8;  

typedef __IO int32_t  vs32;

typedef __IO int16_t  vs16;

typedef __IO int8_t   vs8;

typedef __I int32_t vsc32;  

typedef __I int16_t vsc16;  

typedef __I int8_t vsc8;  

typedef uint32_t  u32;

typedef uint16_t u16;

typedef uint8_t  u8;

typedef const uint32_t uc32;  

typedef const uint16_t uc16;  

typedef const uint8_t uc8;  

typedef __IO uint32_t  vu32;

typedef __IO uint16_t vu16;

typedef __IO uint8_t  vu8;

typedef __I uint32_t vuc32;  

typedef __I uint16_t vuc16;  

typedef __I uint8_t vuc8;  

固件库与CMSIS数据类型对比

表格摘自 http://forum.eepw.com.cn/thread/215752/1

变量声明宏定义及重命名基本都在此了！