STM32 variable type definition and extension

Note: Data operations may exceed the type of variable definition, so be careful when defining variables!

Variable type definition in STM32F4: in stdint

    /* exact-width signed integer types */

typedef signed char int8_t;

typedef signed short int int16_t;

typedef signed int int32_t; //In a 32-bit environment, int represents 4 bytes 32 bits

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;

#if !defined(__cplusplus) || defined(__STDC_LIMIT_MACROS)

    /* 7.18.2.1 */

    /* minimum values ​​of exact-width signed integer types */

#define INT8_MIN -128

#define INT16_MIN -32768

#define INT32_MIN (~0x7fffffff) /* -2147483648 is unsigned */

#define INT64_MIN __INT64_C(~0x7fffffffffffffff) /* -9223372036854775808 is unsigned */

    /* maximum values ​​of exact-width signed integer types */

#define INT8_MAX 127

#define INT16_MAX 32767

#define INT32_MAX 2147483647

#define INT64_MAX __INT64_C(9223372036854775807)

    /* maximum values ​​of exact-width unsigned integer types */

#define UINT8_MAX 255

#define UINT16_MAX 65535

#define UINT32_MAX 4294967295u

#define UINT64_MAX __UINT64_C(18446744073709551615)

 Reference: https://blog.csdn.net/f1engmin11/article/details/70946471 and the same as the above library file