c语言u8是什么_c语言中unsigned char什么意思

ST库里面的宏定义，定义如下：

#define      __I        volatile const          /*!< defines ‘read only’ permissions      */

#define      __O       volatile                  /*!< defines ‘write only’ permissions     */

#define     __IO      volatile                  /*!< defines ‘read / write’ permissions   */

typedef unsigned int            uint32_t;

typedef unsigned long  u32;

typedef uint32_t  u32

/* Exported types ————————————————————*/

typedef signed long  s32;

typedef signed short s16;

typedef signed char  s8;

typedef signed long  const sc32;  /* Read Only */

typedef signed short const sc16;  /* Read Only */

typedef signed char  const sc8;   /* Read Only */

typedef volatile signed long  vs32;

typedef volatile signed short vs16;

typedef volatile signed char  vs8;

typedef volatile signed long  const vsc32;  /* Read Only */

typedef volatile signed short const vsc16;  /* Read Only */

typedef volatile signed char  const vsc8;   /* Read Only */

typedef unsigned long  u32;

typedef unsigned short u16;

typedef unsigned char  u8;

typedef unsigned long  const uc32;  /* Read Only */

typedef unsigned short const uc16;  /* Read Only */

typedef unsigned char  const uc8;   /* Read Only */

typedef volatile unsigned long  vu32;

typedef volatile unsigned short vu16;

typedef volatile unsigned char  vu8;

typedef volatile unsigned long  const vuc32;  /* Read Only */

typedef volatile unsigned short const vuc16;  /* Read Only */

typedef volatile unsigned char  const vuc8;   /* Read Only */

Exported_types

类型定义

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