stm32 优先级说明[通俗易懂]

抢占优先级和响应优先级。事实上是一个中断所包括的两个优先级，当中前者是对抢占优先级的级别划分，后者是同样抢占优先级的优先级别的划分。
比方：
中断A抢占优先级比B高，那么A的中断能够在B里面触发，忽略响应优先级；
A和B抢占优先级同样，则A、B的响应优先级决定谁先响应。

总之 , 抢占优先级厉害
详细我们能够參考官方提供的table
00080 The table below gives the allowed values of the pre-emption priority and subpriority according
00081 to the Priority Grouping configuration performed by NVIC_PriorityGroupConfig function
00082 ============================================================================================================================
00083 NVIC_PriorityGroup | NVIC_IRQChannelPreemptionPriority | NVIC_IRQChannelSubPriority | Description
00084 ============================================================================================================================
00085 NVIC_PriorityGroup_0 | 0 | 0-15 | 0 bits for pre-emption priority
00086 | | | 4 bits for subpriority
00087 —————————————————————————————————————————-
00088 NVIC_PriorityGroup_1 | 0-1 | 0-7 | 1 bits for pre-emption priority
00089 | | | 3 bits for subpriority
00090 —————————————————————————————————————————-
00091 NVIC_PriorityGroup_2 | 0-3 | 0-3 | 2 bits for pre-emption priority
00092 | | | 2 bits for subpriority
00093 —————————————————————————————————————————-
00094 NVIC_PriorityGroup_3 | 0-7 | 0-1 | 3 bits for pre-emption priority
00095 | | | 1 bits for subpriority
00096 —————————————————————————————————————————-
00097 NVIC_PriorityGroup_4 | 0-15 | 0 | 4 bits for pre-emption priority
00098 | | | 0 bits for subpriority
00099 ============================================================================================================================