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OUTPUT the Clock named as MCO IN STM32

作者:互联网

配置PB3为Alternate Function

配置输出模式

如何确定端口和PIN地址?

GPIOBBASE = 0X40010C00;

(GPIOBBASE + 0X00) |= unint32_t(0X0) << 12; /配置CNF3,pp模式/
运算符优先级:赋值运算符最后 < 移位运算 < 一元运算符 < 后缀运算符
(GPIOBBASE + 0X00ul) |= unint32_t(0X11UL) << 12U; /配置MODE3,50Mhz
/
确定alternate function 时钟是否开启?

RCCBASE = 0X40021000;
(RCCBASE + 0X18ul) |= unint32_t(0x1UL);/RCC_APB2ENR开启*/

U表示无符号型,UL无符号长整型;系统默认数值为int类型,是有符号类型;
配置选择输出的时钟

*(RCCBASE + 0X04ul) |= unint32_t(0x101ul) << 24u;
以下为LL库的内容摘抄

点击查看代码
#define LED2_PIN                           LL_GPIO_PIN_8
#define LED2_GPIO_PORT                     GPIOB
#define LED2_GPIO_CLK_ENABLE()             LL_APB2_GRP1_EnableClock(LL_APB2_GRP1_PERIPH_GPIOB)/*LED2_GPIO_CLK_ENABLE() 是被调用的函数*/
#define LL_APB2_GRP1_PERIPH_GPIOB          RCC_APB2ENR_IOPBEN
#define RCC_APB2ENR_IOPBEN_Pos               (3U)                              
#define RCC_APB2ENR_IOPBEN_Msk               (0x1UL << RCC_APB2ENR_IOPBEN_Pos)  /*!< 0x00000008 */
#define RCC_APB2ENR_IOPBEN                   RCC_APB2ENR_IOPBEN_Msk            
#define SET_BIT(REG, BIT)     ((REG) |= (BIT))
#define RCC_BASE              (AHBPERIPH_BASE + 0x00001000UL)
typedef struct
{
  __IO uint32_t CR;
  __IO uint32_t CFGR;
  __IO uint32_t CIR;
  __IO uint32_t APB2RSTR;
  __IO uint32_t APB1RSTR;
  __IO uint32_t AHBENR;
  __IO uint32_t APB2ENR;
  __IO uint32_t APB1ENR;
  __IO uint32_t BDCR;
  __IO uint32_t CSR;


} RCC_TypeDef;
#define RCC                 ((RCC_TypeDef *)RCC_BASE) /**RCC被定义为RCC_TypeDef类型指针**/
  SET_BIT(RCC->APB2ENR, Periphs); /**RCC->APB2ENR通过指针访问变量**/

标签:MCO,named,LL,APB2ENR,运算符,GPIO,OUTPUT,define,RCC
来源: https://www.cnblogs.com/DB-twilight/p/16665445.html