zhj失落之地 2018-01-10 21:23:12 1196 收藏 5
分类专栏： stm32相关
最后发布:2018-01-10 21:23:12首次发布:2018-01-10 21:23:12
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在STM32的固件库和提供的例程中，到处都可以见到assert_param()的使用。在固件库中，它的作用就是检测传递给函数的参数是否是有效的参数。 所谓有效的参数是指满足规定范围的参数，比如某个参数的取值范围只能是小于3的正整数，如果给出的参数大于3，则这个assert_param()可以在运行的程序调用到这个函数时报告错误，使程序员可以及时发现错误，而不必等到程序运行结果的错误而大费周折。
这是一种常见的软件技术，可以在调试阶段帮助程序员快速地排除那些明显的错误。 它确实在程序的运行上牺牲了效率(但只是在调试阶段)，但在项目的开发上却帮助你提高了效率。 当你的项目开发成功，使用release模式编译之后，或在stm32f10x_conf.h文件中注释掉对USE_FULL_ASSERT的宏定义，所有的assert_param()检验都消失了，不会影响最终程序的运行效率。 摘抄于库函数stm32f0xx_conf.h中：#ifdef USE_FULL_ASSERT #define assert_param(expr) ((expr) ? (void)0 : assert_failed((uint8_t *)__FILE__, __LINE__)) /* Exported functions ------------------------------------------------------- */ void assert_failed(uint8_t* file, uint32_t line); #else #define assert_param(expr) ((void)0) #endif /* USE_FULL_ASSERT */ 如果定义了USE_FULL_ASSERT，就把 assert_param(expr) 定义为((expr) ? (void)0 : assert_failed((uint8_t *)__FILE__, __LINE__)) 并申明一下assert_failed这个函数。否则把assert_param(expr)定义为空。 __FILE__和__LINE__是IAR定义的宏，指的是当前的编译的文件名和行数。 整个宏作用为：如果expr为真，则什么也不返回，如果expr为假，则调用assert_failed()这个出错程序。
举例：
#define IS_GPIO_MODE(MODE) (((MODE) == GPIO_Mode_IN) || ((MODE) ==GPIO_Mode_OUT) || ((MODE) == )
|| ((MODE) == GPIO_Mode_AN)) void GPIO_Init(GPIO_TypeDef* GPIOx, GPIO_InitTypeDef* GPIO_InitStruct) { /* Check the parameters */ assert_param(IS_GPIO_MODE(GPIO_InitStruct->GPIO_Mode)); } GPIO_InitStruct->GPIO_Mode是枚举类型，只能是GPIO_Mode_IN、GPIO_Mode_OUT、GPIO_Mode_AF、GPIO_Mode_AN中一个，因此宏定义IS_GPIO_MODE(MODE)能判断是其中一个为真，否则为假。因此达到调试的目的。 assert_failed()函数完成的具体操作，由用户自己定义。
亲测发现
typedef struct { uint8_t NVIC_IRQChannel; /*!< Specifies the IRQ channel to be enabled or disabled. This parameter can be a value of @ref IRQn_Type (For the complete STM32 Devices IRQ Channels list, please refer to stm32f10x.h file) */
uint8_t NVIC_IRQChannelPreemptionPriority; /*!< Specifies the pre-emption priority for the IRQ channel specified in NVIC_IRQChannel. This parameter can be a value between 0 and 15 as described in the table @ref NVIC_Priority_Table */
uint8_t NVIC_IRQChannelSubPriority; /*!< Specifies the subpriority level for the IRQ channel specified in NVIC_IRQChannel. This parameter can be a value between 0 and 15 as described in the table @ref NVIC_Priority_Table */
FunctionalState NVIC_IRQChannelCmd; /*!< Specifies whether the IRQ channel defined in NVIC_IRQChannel will be enabled or disabled. This parameter can be set either to ENABLE or DISABLE */ } NVIC_InitTypeDef;
void NVIC_Init(NVIC_InitTypeDef* NVIC_InitStruct) { uint32_t tmppriority = 0x00, tmppre = 0x00, tmpsub = 0x0F; /* Check the parameters */ //没有检查NVIC_IRQChannelCmd参数的函数，经过查资料发现assert_param有没有都可以，只是为了调试方便2020.11.4 assert_param(IS_FUNCTIONAL_STATE(NVIC_InitStruct->NVIC_IRQChannelCmd)); assert_param(IS_NVIC_PREEMPTION_PRIORITY(NVIC_InitStruct->NVIC_IRQChannelPreemptionPriority)); assert_param(IS_NVIC_SUB_PRIORITY(NVIC_InitStruct->NVIC_IRQChannelSubPriority)); if (NVIC_InitStruct->NVIC_IRQChannelCmd != DISABLE) { /* Compute the Corresponding IRQ Priority --------------------------------*/ tmppriority = (0x700 - ((SCB->AIRCR) & (uint32_t)0x700))>> 0x08; tmppre = (0x4 - tmppriority); tmpsub = tmpsub >> tmppriority;
tmppriority = (uint32_t)NVIC_InitStruct->NVIC_IRQChannelPreemptionPriority << tmppre; tmppriority |= NVIC_InitStruct->NVIC_IRQChannelSubPriority & tmpsub; tmppriority = tmppriority << 0x04; NVIC->IP[NVIC_InitStruct->NVIC_IRQChannel] = tmppriority; /* Enable the Selected IRQ Channels --------------------------------------*/ NVIC->ISER[NVIC_InitStruct->NVIC_IRQChannel >> 0x05] = (uint32_t)0x01 << (NVIC_InitStruct->NVIC_IRQChannel & (uint8_t)0x1F); } else { /* Disable the Selected IRQ Channels -------------------------------------*/ NVIC->ICER[NVIC_InitStruct->NVIC_IRQChannel >> 0x05] = (uint32_t)0x01 << (NVIC_InitStruct->NVIC_IRQChannel & (uint8_t)0x1F); } }
另一例是有参数检查
typedef struct { uint32_t EXTI_Line; /*!< Specifies the EXTI lines to be enabled or disabled. This parameter can be any combination of @ref EXTI_Lines */ EXTIMode_TypeDef EXTI_Mode; /*!< Specifies the mode for the EXTI lines. This parameter can be a value of @ref EXTIMode_TypeDef */
EXTITrigger_TypeDef EXTI_Trigger; /*!< Specifies the trigger signal active edge for the EXTI lines. This parameter can be a value of @ref EXTIMode_TypeDef */
FunctionalState EXTI_LineCmd; /*!< Specifies the new state of the selected EXTI lines. This parameter can be set either to ENABLE or DISABLE */ }EXTI_InitTypeDef;
void EXTI_Init(EXTI_InitTypeDef* EXTI_InitStruct) { uint32_t tmp = 0;
/* Check the parameters */ assert_param(IS_EXTI_MODE(EXTI_InitStruct->EXTI_Mode)); assert_param(IS_EXTI_TRIGGER(EXTI_InitStruct->EXTI_Trigger)); assert_param(IS_EXTI_LINE(EXTI_InitStruct->EXTI_Line)); assert_param(IS_FUNCTIONAL_STATE(EXTI_InitStruct->EXTI_LineCmd));//有这个参数检查项目2020.11.4
tmp = (uint32_t)EXTI_BASE; if (EXTI_InitStruct->EXTI_LineCmd != DISABLE) { /* Clear EXTI line configuration */ EXTI->IMR &= ~EXTI_InitStruct->EXTI_Line; EXTI->EMR &= ~EXTI_InitStruct->EXTI_Line; tmp += EXTI_InitStruct->EXTI_Mode;
*(__IO uint32_t *) tmp |= EXTI_InitStruct->EXTI_Line;
/* Clear Rising Falling edge configuration */ EXTI->RTSR &= ~EXTI_InitStruct->EXTI_Line; EXTI->FTSR &= ~EXTI_InitStruct->EXTI_Line; /* Select the trigger for the selected external interrupts */ if (EXTI_InitStruct->EXTI_Trigger == EXTI_Trigger_Rising_Falling) { /* Rising Falling edge */ EXTI->RTSR |= EXTI_InitStruct->EXTI_Line; EXTI->FTSR |= EXTI_InitStruct->EXTI_Line; } else { tmp = (uint32_t)EXTI_BASE; tmp += EXTI_InitStruct->EXTI_Trigger;
*(__IO uint32_t *) tmp |= EXTI_InitStruct->EXTI_Line; } } else { tmp += EXTI_InitStruct->EXTI_Mode;
/* Disable the selected external lines */ *(__IO uint32_t *) tmp &= ~EXTI_InitStruct->EXTI_Line; } }
