stm32 数据类型的定义及常用的U8,U16,U32是什么
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 (C语言标准表达方法)
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?
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(主要是V2.0)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 volatile
stm32f10x.h 这个文件主要是为了兼容旧版本吧 typedef int32_ts32;
typedef int16_t s16;
typedef int8_ts8;
typedef const int32_t sc32;
typedef const int16_t sc16;
typedef const int8_t sc8;
typedef __IO int32_tvs32;
typedef __IO int16_tvs16;
typedef __IO int8_t vs8;
typedef __I int32_t vsc32;
typedef __I int16_t vsc16;
typedef __I int8_t vsc8;
typedef uint32_tu32;
typedef uint16_t u16;
typedef uint8_tu8;
typedef const uint32_t uc32;
typedef const uint16_t uc16;
typedef const uint8_t uc8;
typedef __IO uint32_tvu32;
typedef __IO uint16_t vu16;
typedef __IO uint8_tvu8;
typedef __I uint32_t vuc32;
typedef __I uint16_t vuc16;
typedef __I uint8_t vuc8;
为了兼容吧,
同时也为了简写
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