中断优先级设置错误会怎样？

跟紧我

如题，维护一个程序，发现中断优先级设置存在明显的错误，而且这几个中断都在正常使用中

• void BOARD_NVIC_Init(void)
• {
•         NVIC_InitTypeDef   NVIC_InitStructure;
•         /* Set the Vector Table base location at 0x08000000 */
•         NVIC_SetVectorTable(NVIC_VectTab_FLASH, 0x0); //设置中断矢量表，加载FLASH的位置
•         /* 2 bit for pre-emption priority, 2 bits for subpriority */
•         NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2); //设置优先级分组
•         /*定时器中断*/
•         NVIC_InitStructure.NVIC_IRQChannel = TIM2_IRQn;
•         NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
•         NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
•         NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
•         NVIC_Init(&NVIC_InitStructure);
•         NVIC_InitStructure.NVIC_IRQChannel = USART1_IRQn; //通道设置为串口1中断
•         NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1; //中断占先等级0
•         NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1; //中断响应优先级0
•         NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //打开中断
•         NVIC_Init(&NVIC_InitStructure);
•         NVIC_InitStructure.NVIC_IRQChannel = USART2_IRQn; //通道设置为串口2中断
•         NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1; //中断占先等级0
•         NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;               //中断响应优先级0
•         NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;           //打开中断
•         NVIC_Init(&NVIC_InitStructure);
•         NVIC_InitStructure.NVIC_IRQChannel = USART3_IRQn;//通道设置为串口3中断
•         NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 10; //中断占先等级0
•         NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;               //中断响应优先级0
•         NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;           //打开中断
•         NVIC_Init(&NVIC_InitStructure);
•         NVIC_InitStructure.NVIC_IRQChannel = UART4_IRQn;//通道设置为串口4中断
•         NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 10; //中断占先等级0
•         NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;               //中断响应优先级0
•         NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;           //打开中断
•         NVIC_Init(&NVIC_InitStructure);
•     //DMA发送中断设置 (串口3 发送中断)
•     NVIC_InitStructure.NVIC_IRQChannel = DMA1_Channel2_IRQn;
•     NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 3;
•     NVIC_InitStructure.NVIC_IRQChannelSubPriority = 2;
•     NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
•     NVIC_Init(&NVIC_InitStructure);
•         /*外部IO中断*/
•         NVIC_InitStructure.NVIC_IRQChannel = EXTI4_IRQn;
•         NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 4;
•         NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
•         NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
•         NVIC_Init(&NVIC_InitStructure);
•         /*外部IO中断*/
•         NVIC_InitStructure.NVIC_IRQChannel = EXTI9_5_IRQn;
•         NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 4;
•         NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
•         NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
•         NVIC_Init(&NVIC_InitStructure);
• }
  

[color=rgb(51, 102, 153) !important]复制代码
抢占优先级占两位的话，取值应该是0-3，程序中出现了超出预期的取值，我的理解是如果中断号设置错误，存在异常向量表中的数据也应该是错误的，那么程序会不知道从哪里进入中断。但是，很奇葩的是，这个程序运行了一年多，非常稳定（代码中这几个中断都在使用），怀疑是按默认的中断标号来进入的，应该怎么排查

qingmei168

帮顶！！！！！！

跟紧我

应该是配置的值会和0x03（配置优先级分组2）位与操作，得到的值才是最终配置生效的。如配置优先级分组2时，再配置中断抢占优先级为10，则实际配置生效的抢占优先级为0x0A&0x03 =0x02