stm32中的數(shù)據(jù)類(lèi)型定義
STM32F10X.H
1 #include "core_cm3.h"
2 #include "system_stm32f10x.h"
3 #include
4
5 /** @addtogroup Exported_types
6 * @{
7 */
8
9 /*!< STM32F10x Standard Peripheral Library old types (maintained for legacy purpose) */
10 typedef int32_t s32;
11 typedef int16_t s16;
12 typedef int8_t s8;
13
14 typedef const int32_t sc32; /*!< Read Only */
15 typedef const int16_t sc16; /*!< Read Only */
16 typedef const int8_t sc8; /*!< Read Only */
17
18 typedef __IO int32_t vs32;
19 typedef __IO int16_t vs16;
20 typedef __IO int8_t vs8;
21
22 typedef __I int32_t vsc32; /*!< Read Only */
23 typedef __I int16_t vsc16; /*!< Read Only */
24 typedef __I int8_t vsc8; /*!< Read Only */
25
26 typedef uint32_t u32;
27 typedef uint16_t u16;
28 typedef uint8_t u8;
29
30 typedef const uint32_t uc32; /*!< Read Only */
31 typedef const uint16_t uc16; /*!< Read Only */
32 typedef const uint8_t uc8; /*!< Read Only */
33
34 typedef __IO uint32_t vu32;
35 typedef __IO uint16_t vu16;
36 typedef __IO uint8_t vu8;
37
38 typedef __I uint32_t vuc32; /*!< Read Only */
39 typedef __I uint16_t vuc16; /*!< Read Only */
40 typedef __I uint8_t vuc8; /*!< Read Only */
41
42 typedef enum {RESET = 0, SET = !RESET} FlagStatus, ITStatus;
43
44 typedef enum {DISABLE = 0, ENABLE = !DISABLE} FunctionalState;
45 #define IS_FUNCTIONAL_STATE(STATE) (((STATE) == DISABLE) || ((STATE) == ENABLE))
46
47 typedef enum {ERROR = 0, SUCCESS = !ERROR} ErrorStatus;
源定義在#include
1 /*
2 * 'signed' is redundant below, except for 'signed char' and if
3 * the typedef is used to declare a bitfield.
4 */
5
6 /* 7.18.1.1 */
7
8 /* exact-width signed integer types */
9 typedef signed char int8_t;
10 typedef signed short int int16_t;
11 typedef signed int int32_t;
12 typedef signed __INT64 int64_t;
13
14 /* exact-width unsigned integer types */
15 typedef unsigned char uint8_t;
16 typedef unsigned short int uint16_t;
17 typedef unsigned int uint32_t;
18 typedef unsigned __INT64 uint64_t;
19
20 /* 7.18.1.2 */
21
22 /* smallest type of at least n bits */
23 /* minimum-width signed integer types */
24 typedef signed char int_least8_t;
25 typedef signed short int int_least16_t;
26 typedef signed int int_least32_t;
27 typedef signed __INT64 int_least64_t;
28
29 /* minimum-width unsigned integer types */
30 typedef unsigned char uint_least8_t;
31 typedef unsigned short int uint_least16_t;
32 typedef unsigned int uint_least32_t;
33 typedef unsigned __INT64 uint_least64_t;
34
35 /* 7.18.1.3 */
36
37 /* fastest minimum-width signed integer types */
38 typedef signed int int_fast8_t;
39 typedef signed int int_fast16_t;
40 typedef signed int int_fast32_t;
41 typedef signed __INT64 int_fast64_t;
42
43 /* fastest minimum-width unsigned integer types */
44 typedef unsigned int uint_fast8_t;
45 typedef unsigned int uint_fast16_t;
46 typedef unsigned int uint_fast32_t;
47 typedef unsigned __INT64 uint_fast64_t;
48
49 /* 7.18.1.4 integer types capable of holding object pointers */
50 #if __sizeof_ptr == 8
51 typedef signed __INT64 intptr_t;
52 typedef unsigned __INT64 uintptr_t;
53 #else
54 typedef signed int intptr_t;
55 typedef unsigned int uintptr_t;
56 #endif
57
58 /* 7.18.1.5 greatest-width integer types */
59 typedef signed __LONGLONG intmax_t;
60 typedef unsigned __LONGLONG uintmax_t;
由上述可知：
1、有符號(hào)整型
s8 占用1個(gè)byte，數(shù)據(jù)范圍 -2^7 到 (2^7-1)
s16 占用2個(gè)byte，數(shù)據(jù)范圍 -2^15 到 (2^15-1)
s32 占用 4個(gè)byte，數(shù)據(jù)范圍 -2^31 到 (2^31-1)2^31 =2147483647
int64_t占用8個(gè)byte，數(shù)據(jù)范圍 -2^63 到 (2^63-1) 2^63 =9223372036854775807ll
2、無(wú)符號(hào)整型
u8 占用1個(gè)byte， 數(shù)據(jù)范圍 0 - 2^8
u16 占用2個(gè)byte, 數(shù)據(jù)范圍 0 - 2^16
u32 占用4個(gè)byte, 數(shù)據(jù)范圍 0 - 2^32 2^32 =4294967295
uint64_t 占用8個(gè)byte, 數(shù)據(jù)范圍 0 - 2^64 2^64 =18446744073709551615
3、浮點(diǎn)型
float ——4個(gè)byte，有符號(hào)型，可以表達(dá)負(fù)數(shù)/小數(shù)；Float 類(lèi)型至少要能精確表示到小數(shù)點(diǎn)后6位。
double——8個(gè)byte，有符號(hào)型，可以表達(dá)負(fù)數(shù)/小數(shù)；Double 類(lèi)型至少要能精確到小數(shù)點(diǎn)后 10 位。
二、不同數(shù)據(jù)類(lèi)型混合運(yùn)算在C語(yǔ)言中，不同類(lèi)型的數(shù)據(jù)間是可以混合運(yùn)算的。在進(jìn)行運(yùn)算時(shí)，不同類(lèi)型的數(shù)據(jù)要先轉(zhuǎn)換成同一類(lèi)型，然后進(jìn)行運(yùn)算。轉(zhuǎn)換的規(guī)則如下：
注意：箭頭的方向只表示數(shù)據(jù)類(lèi)型級(jí)別的高低，由低向高轉(zhuǎn)換，這個(gè)轉(zhuǎn)換過(guò)程是一步到位的。
（三）數(shù)據(jù)類(lèi)型轉(zhuǎn)換規(guī)則
各類(lèi)數(shù)據(jù)類(lèi)型的轉(zhuǎn)換，分為兩種方式：隱式（編譯軟件自動(dòng)完成），顯式（程序強(qiáng)制轉(zhuǎn)換）
隱式轉(zhuǎn)換規(guī)則：
字符必須先轉(zhuǎn)換為整數(shù)(C語(yǔ)言規(guī)定字符類(lèi)型數(shù)據(jù)和整型數(shù)據(jù)之間可以通用)
short型轉(zhuǎn)換為int型(同屬于整型)
float型數(shù)據(jù)在運(yùn)算時(shí)一律轉(zhuǎn)換為雙精度(double)型，以提高運(yùn)算精度(同屬于實(shí)型)
賦值時(shí)，一律是右部值轉(zhuǎn)換為左部類(lèi)型
[注]
當(dāng)整型數(shù)據(jù)和雙精度數(shù)據(jù)進(jìn)行運(yùn)算時(shí)，C先將整型數(shù)據(jù)轉(zhuǎn)換成雙精度型數(shù)據(jù)，再進(jìn)行運(yùn)算，結(jié)果為雙精度類(lèi)型數(shù)據(jù)
當(dāng)字符型數(shù)據(jù)和實(shí)型數(shù)據(jù)進(jìn)行運(yùn)算時(shí)，C先將字符型數(shù)據(jù)轉(zhuǎn)換成實(shí)型數(shù)據(jù)，然后進(jìn)行計(jì)算，結(jié)果為實(shí)型數(shù)據(jù)
顯式轉(zhuǎn)換規(guī)則：
例：(int)(x+y);
注：強(qiáng)制類(lèi)型轉(zhuǎn)換時(shí)，得到一個(gè)所需要的中間變量，原來(lái)變量的類(lèi)型未發(fā)生變化。
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