嵌入式单片机开发 - HAL 库 STM32F1 外设的时钟使能（时钟使能宏、时钟禁用宏）

概述

1. STM32 外设的时钟使能宏（ENABLE 系列）与时钟禁用宏（DISABLE系列）位于 STM32F1xx_hal_rcc.h

2. 下面主要以 APB2 总线上的外设的时钟使能宏与时钟禁用宏为例

一、时钟使能宏

1、基本介绍

#define __HAL_RCC_AFIO_CLK_ENABLE()   do { \
                                        __IO uint32_t tmpreg; \
                                        SET_BIT(RCC->APB2ENR, RCC_APB2ENR_AFIOEN);\
                                        /* Delay after an RCC peripheral clock enabling */\
                                        tmpreg = READ_BIT(RCC->APB2ENR, RCC_APB2ENR_AFIOEN);\
                                        UNUSED(tmpreg); \
                                      } while(0U)

#define __HAL_RCC_GPIOA_CLK_ENABLE()   do { \
                                        __IO uint32_t tmpreg; \
                                        SET_BIT(RCC->APB2ENR, RCC_APB2ENR_IOPAEN);\
                                        /* Delay after an RCC peripheral clock enabling */\
                                        tmpreg = READ_BIT(RCC->APB2ENR, RCC_APB2ENR_IOPAEN);\
                                        UNUSED(tmpreg); \
                                      } while(0U)

#define __HAL_RCC_GPIOB_CLK_ENABLE()   do { \
                                        __IO uint32_t tmpreg; \
                                        SET_BIT(RCC->APB2ENR, RCC_APB2ENR_IOPBEN);\
                                        /* Delay after an RCC peripheral clock enabling */\
                                        tmpreg = READ_BIT(RCC->APB2ENR, RCC_APB2ENR_IOPBEN);\
                                        UNUSED(tmpreg); \
                                      } while(0U)

#define __HAL_RCC_GPIOC_CLK_ENABLE()   do { \
                                        __IO uint32_t tmpreg; \
                                        SET_BIT(RCC->APB2ENR, RCC_APB2ENR_IOPCEN);\
                                        /* Delay after an RCC peripheral clock enabling */\
                                        tmpreg = READ_BIT(RCC->APB2ENR, RCC_APB2ENR_IOPCEN);\
                                        UNUSED(tmpreg); \
                                      } while(0U)

#define __HAL_RCC_GPIOD_CLK_ENABLE()   do { \
                                        __IO uint32_t tmpreg; \
                                        SET_BIT(RCC->APB2ENR, RCC_APB2ENR_IOPDEN);\
                                        /* Delay after an RCC peripheral clock enabling */\
                                        tmpreg = READ_BIT(RCC->APB2ENR, RCC_APB2ENR_IOPDEN);\
                                        UNUSED(tmpreg); \
                                      } while(0U)

#define __HAL_RCC_ADC1_CLK_ENABLE()   do { \
                                        __IO uint32_t tmpreg; \
                                        SET_BIT(RCC->APB2ENR, RCC_APB2ENR_ADC1EN);\
                                        /* Delay after an RCC peripheral clock enabling */\
                                        tmpreg = READ_BIT(RCC->APB2ENR, RCC_APB2ENR_ADC1EN);\
                                        UNUSED(tmpreg); \
                                      } while(0U)

#define __HAL_RCC_TIM1_CLK_ENABLE()   do { \
                                        __IO uint32_t tmpreg; \
                                        SET_BIT(RCC->APB2ENR, RCC_APB2ENR_TIM1EN);\
                                        /* Delay after an RCC peripheral clock enabling */\
                                        tmpreg = READ_BIT(RCC->APB2ENR, RCC_APB2ENR_TIM1EN);\
                                        UNUSED(tmpreg); \
                                      } while(0U)

#define __HAL_RCC_SPI1_CLK_ENABLE()   do { \
                                        __IO uint32_t tmpreg; \
                                        SET_BIT(RCC->APB2ENR, RCC_APB2ENR_SPI1EN);\
                                        /* Delay after an RCC peripheral clock enabling */\
                                        tmpreg = READ_BIT(RCC->APB2ENR, RCC_APB2ENR_SPI1EN);\
                                        UNUSED(tmpreg); \
                                      } while(0U)

#define __HAL_RCC_USART1_CLK_ENABLE()   do { \
                                        __IO uint32_t tmpreg; \
                                        SET_BIT(RCC->APB2ENR, RCC_APB2ENR_USART1EN);\
                                        /* Delay after an RCC peripheral clock enabling */\
                                        tmpreg = READ_BIT(RCC->APB2ENR, RCC_APB2ENR_USART1EN);\
                                        UNUSED(tmpreg); \
                                      } while(0U)

• 这些时钟使能宏的结构相同，只是针对不同的外设

2、解读

#define __HAL_RCC_AFIO_CLK_ENABLE()   do { \
                                        __IO uint32_t tmpreg; \
                                        SET_BIT(RCC->APB2ENR, RCC_APB2ENR_AFIOEN);\
                                        /* Delay after an RCC peripheral clock enabling */\
                                        tmpreg = READ_BIT(RCC->APB2ENR, RCC_APB2ENR_AFIOEN);\
                                        UNUSED(tmpreg); \
                                      } while(0U)

• 以 __HAL_RCC_AFIO_CLK_ENABLE() 为例

1. 使用 do { ... } while(0) 结构，确保宏在使用时的安全性

2. 声明一个临时变量 tmpreg

3. SET_BIT 设置 RCC->APB2ENR 寄存器中对应的位，这里是 RCC_APB2ENR_AFIOEN

#define SET_BIT(REG, BIT)     ((REG) |= (BIT))

4. READ_BIT 读取该位值到临时变量，这个操作是为了插入延迟，确保时钟稳定，即读取操作会在写入操作之后

#define READ_BIT(REG, BIT)    ((REG) & (BIT))

5. UNUSED(tmpreg) 避免编译器警告未使用的变量

3、演示

// 使能 GPIOA 和 GPIOB 的时钟
__HAL_RCC_GPIOB_CLK_ENABLE();
__HAL_RCC_GPIOE_CLK_ENABLE();

二、时钟禁用宏

1、基本介绍

#define __HAL_RCC_AFIO_CLK_DISABLE()      (RCC->APB2ENR &= ~(RCC_APB2ENR_AFIOEN))
#define __HAL_RCC_GPIOA_CLK_DISABLE()     (RCC->APB2ENR &= ~(RCC_APB2ENR_IOPAEN))
#define __HAL_RCC_GPIOB_CLK_DISABLE()     (RCC->APB2ENR &= ~(RCC_APB2ENR_IOPBEN))
#define __HAL_RCC_GPIOC_CLK_DISABLE()     (RCC->APB2ENR &= ~(RCC_APB2ENR_IOPCEN))
#define __HAL_RCC_GPIOD_CLK_DISABLE()     (RCC->APB2ENR &= ~(RCC_APB2ENR_IOPDEN))
#define __HAL_RCC_ADC1_CLK_DISABLE()      (RCC->APB2ENR &= ~(RCC_APB2ENR_ADC1EN))

#define __HAL_RCC_TIM1_CLK_DISABLE()      (RCC->APB2ENR &= ~(RCC_APB2ENR_TIM1EN))
#define __HAL_RCC_SPI1_CLK_DISABLE()      (RCC->APB2ENR &= ~(RCC_APB2ENR_SPI1EN))
#define __HAL_RCC_USART1_CLK_DISABLE()    (RCC->APB2ENR &= ~(RCC_APB2ENR_USART1EN))

• 这些时钟禁用宏的结构相同，只是针对不同的外设

2、解读

#define __HAL_RCC_AFIO_CLK_DISABLE()      (RCC->APB2ENR &= ~(RCC_APB2ENR_AFIOEN))

• 以 __HAL_RCC_AFIO_CLK_DISABLE() 为例，直接使用 RCC->APB2ENR 寄存器，然后使用按位与操作 &= 来清除对应的位，这里是 RCC_APB2ENR_AFIOEN

3、演示

// 禁用 GPIOA 和 GPIOB 的时钟
__HAL_RCC_GPIOB_CLK_DISABLE();
__HAL_RCC_GPIOE_CLK_DISABLE();