目前棘手求助问题:
在飞思卡尔头文件中有如下定义
#define SIM_BASE (0x40047000u)
/** Peripheral SIM base pointer */
#define SIM ((SIM_Type *)SIM_BASE)
typedef struct {
__IO uint32_t SOPT1; /**< System Op
tions Register 1, offset: 0x0 */
__IO uint32_t SOPT1CFG; /**< SOPT1 Configuration Register, offset: 0x4 */
uint8_t RESERVED_0[4092];
__IO uint32_t SOPT2; /**< System Options Register 2, offset: 0x1004 */
uint8_t RESERVED_1[4];
__IO uint32_t SOPT4; /**< System Options Register 4, offset: 0x100C */
__IO uint32_t SOPT5; /**< System Options Register 5, offset: 0x1010 */
uint8_t RESERVED_2[4];
__IO uint32_t SOPT7; /**< System Options Register 7, offset: 0x1018 */
uint8_t RESERVED_3[8];
__I uint32_t SDID; /**< System Device Identification Register, offset: 0x1024 */
uint8_t RESERVED_4[12];
__IO uint32_t SCGC4; /**< System Clock Gating Control Register 4, offset: 0x1034 */
__IO uint32_t SCGC5; /**< System Clock Gating Control Register 5, offset: 0x1038 */
__IO uint32_t SCGC6; /**< System Clock Gating Control Register 6, offset: 0x103C */
__IO uint32_t SCGC7; /**< System Clock Gating Control Register 7, offset: 0x1040 */
__IO uint32_t CLKDIV1; /**< System Clock Divider Register 1, offset: 0x1044 */
uint8_t RESERVED_5[4];
__IO uint32_t FCFG1; /**< Flash Configuration Register 1, offset: 0x104C */
__I uint32_t FCFG2; /**< Flash Configuration Register 2, offset: 0x1050 */
uint8_t RESERVED_6[4];
__I uint32_t UIDMH; /**< Unique Identification Register Mid-High, offset: 0x1058 */
__I uint32_t UIDML; /**< Unique Identification Register Mid Low, offset: 0x105C */
__I uint32_t UIDL; /**< Unique Identification Register Low, offset: 0x1060 */
uint8_t RESERVED_7[156];
__IO uint32_t COPC; /**< COP Control Register, offset: 0x1100 */
__O uint32_t SRVCOP; /**< Service COP Register, offset: 0x1104 */
} SIM_Type;
问题是:
#define SIM_BASE (0x40047000u)中0x40047000u最后面的u是什么含义?
#define SIM ((SIM_Type *)SIM_BASE)中 ((SIM_Type *)SIM_BASE)什么意思,是代表((SIM_Type*)(0x40047000u)的意思么?中间*是什么作用?指针的意思?是指向了那个地址?
往期问题与解答:
今天拿到
开发板经过一番折腾导入固件升级后,终于好了。开始跟着视频想搭建工程文件问题出现了,没发现飞思卡尔芯片类型,求大神指导,不废话了,直接上图。