Stm32之NVIC_PriorityGroup_0

NVIC_PriorityGroup_0是几个抢占优先级 + 响应优先级，如何实现16个中断呢？

想明确 NVIC_PriorityGroup_0 的优先级拆分规则，以及用它配置 16 个中断的具体组合方案，下面清晰拆解并给出可直接使用的配置示例。

NVIC_PriorityGroup_0 的核心定义
NVIC_PriorityGroup_0 是 STM32 NVIC 优先级分组中最特殊的一种，对 4 位优先级寄存器的拆分规则为：
抢占优先级：0 位 → 仅 1 个级别（固定为 0，所有中断抢占优先级相同）
响应优先级：4 位 → 共 16 个级别（0~15，数值越小优先级越高）
总组合数：1 × 16 = 16 种 → 刚好能覆盖 16 个中断的优先级配置需求
核心特点：所有中断无抢占能力（因为抢占优先级都为 0），仅能通过响应优先级决定执行顺序，适合无需中断嵌套、低实时性的场景。
能否实现 16 个中断？
完全可以！该分组下的 16 种响应优先级（0~15）刚好能为 16 个中断分配唯一的优先级，满足 16 个中断的配置需求。
16 个中断的具体组合配置示例
假设你有 16 个典型中断（EXTI0_{EXTI7、USART1}USART3、TIM1~TIM4、SPI1、SPI2），以下是完整的配置代码，按响应优先级从 0（最高）到 15（最低）分配：
c
运行
#include "stm32f10x.h"

void NVIC_Config_16IRQ_Group0(void)

{

NVIC_InitTypeDef NVIC_InitStructure;

复制代码

// 第一步：配置优先级分组为Group_0（0位抢占 + 4位响应）
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_0);

// ==================== 所有中断抢占优先级固定为0 ====================
// 中断1：EXTI0（抢占0，响应0）→ 最高优先级
NVIC_InitStructure.NVIC_IRQChannel = EXTI0_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0; // 必须为0
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;        // 响应优先级0
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);

// 中断2：EXTI1（抢占0，响应1）
NVIC_InitStructure.NVIC_IRQChannel = EXTI1_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);

// 中断3：EXTI2（抢占0，响应2）
NVIC_InitStructure.NVIC_IRQChannel = EXTI2_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 2;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);

// 中断4：EXTI3（抢占0，响应3）
NVIC_InitStructure.NVIC_IRQChannel = EXTI3_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 3;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);

// 中断5：EXTI4（抢占0，响应4）
NVIC_InitStructure.NVIC_IRQChannel = EXTI4_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 4;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);

// 中断6：EXTI5（抢占0，响应5）
NVIC_InitStructure.NVIC_IRQChannel = EXTI5_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 5;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);

// 中断7：EXTI6（抢占0，响应6）
NVIC_InitStructure.NVIC_IRQChannel = EXTI6_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 6;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);

// 中断8：EXTI7（抢占0，响应7）
NVIC_InitStructure.NVIC_IRQChannel = EXTI7_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 7;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);

// 中断9：USART1（抢占0，响应8）
NVIC_InitStructure.NVIC_IRQChannel = USART1_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 8;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);

// 中断10：USART2（抢占0，响应9）
NVIC_InitStructure.NVIC_IRQChannel = USART2_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 9;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);

// 中断11：USART3（抢占0，响应10）
NVIC_InitStructure.NVIC_IRQChannel = USART3_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 10;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);

// 中断12：TIM1（抢占0，响应11）
NVIC_InitStructure.NVIC_IRQChannel = TIM1_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 11;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);

// 中断13：TIM2（抢占0，响应12）
NVIC_InitStructure.NVIC_IRQChannel = TIM2_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 12;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);

// 中断14：TIM3（抢占0，响应13）
NVIC_InitStructure.NVIC_IRQChannel = TIM3_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 13;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);

// 中断15：SPI1（抢占0，响应14）
NVIC_InitStructure.NVIC_IRQChannel = SPI1_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 14;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);

// 中断16：SPI2（抢占0，响应15）→ 整体最低优先级
NVIC_InitStructure.NVIC_IRQChannel = SPI2_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 15;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);

}

关键注意点（Group_0 特有）

抢占优先级必须设 0：如果误将抢占优先级设为 1/2 等非 0 值，NVIC 会忽略该配置，仍按 0 处理，不会报错但优先级逻辑会混乱；

无中断嵌套能力：比如 EXTI0 中断正在执行时，即使 SPI2 中断触发，也必须等 EXTI0 执行完毕才能响应，无法打断；

响应优先级范围：仅能配置 0~15，超出该范围的数值会被 NVIC 自动截断（比如设 16 会被当作 0 处理）。

16 个中断的优先级排序

整体优先级从高到低严格对应响应优先级：

EXTI0(0) > EXTI1(1) > ... > EXTI7(7) > USART1(8) > ... > SPI2(15)

总结

NVIC_PriorityGroup_0 是 0 位抢占优先级 + 4 位响应优先级，仅 1 个抢占级别、16 个响应级别，总 16 种组合；

完全支持 16 个中断的配置，只需为每个中断分配唯一的响应优先级（0~15），抢占优先级固定设 0；

核心特点：无中断嵌套、仅按响应优先级排队执行，适合对实时性要求低、无需中断打断的场景。