15stm32 数据类型的定义.docx
15stm32 数据类型的定义在Keil MDK 开发环境里，比如一个 无符号32位整形数据会有很多种表示方法：1，unsigned int 32 2，uint32_t ; 3 ,u32; 这三种方式都是在表达同一个意思，可为什么ST的开发人员要搞的这么乱呢？ 还有其他好多你可能看起来很陌生 ，很不好理解的表达方式，如：_IO int32_t 他等同于vs32，不过他还等同于 volatile int32_t, 还等同于 volatile signed int 32;最后这种表达方式才是C语言的标准表达方式，够乱吧，能把初学者弄的晕头转向。u8,u16,u32都是unsigned char类型,不过u8是一个字节的,u16是2字节,u32是4字节 typed.u8 是 unsigned charu16 是 unsigned shortu32 是 unsigned intu8 最大255 u16最大65535 就这个意思u8 a=255 a+1=0 u16 b=255 b+1=256其实ST 搞这么多花样，无非是想开发人员在写代码时定义数据类型能少写几个符号，然后又因为前后版本升级，为了兼容旧版本才会出现这么多表示方法。不管他怎么换，都是基于标准C来的，看清楚以下几个文件你就OK了：core_cm3.h ；stm32f10x.h; stdint.h; 其中每个文件大概作用如下：stdint.h 这里放着C语言的标准表达方式/第36行开始typedef signed char int8_t; / 标准表达方式 signed char 被等同于 int8_t；typedef signed short int int16_t;typedef signed int int32_t;/在32位环境里，int代表4个字节32位！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;core_cm3.h 文件主要针对动态 静态 变量修饰符做出类型扩展#ifdef _cplusplus#define _I volatile #else#define _I volatile const #endif#define _O volatile#define _IO volatilestm32f10x.h 这个文件主要是为了兼容旧版本吧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;
