CH579文档有说中断优先级可设置,但却没有相关寄存器说明。
例程中有关于中断优先级函数,但也没有相关设置说明,有多少个等级,以及嵌套中断等信息。
/** \brief Set Interrupt Priority
The function sets the priority of an interrupt.
\note The priority cannot be set for every core interrupt.
\param [in] IRQn Interrupt number.
\param [in] priority Priority to set.
*/
__STATIC_INLINE void NVIC_SetPriority(IRQn_Type IRQn, uint32_t priority)
{
if(IRQn < 0) {
SCB->SHP[_SHP_IDX(IRQn)] = (SCB->SHP[_SHP_IDX(IRQn)] & ~(0xFF << _BIT_SHIFT(IRQn))) |
(((priority << (8 - __NVIC_PRIO_BITS)) & 0xFF) << _BIT_SHIFT(IRQn)); }
else {
NVIC->IP[_IP_IDX(IRQn)] = (NVIC->IP[_IP_IDX(IRQn)] & ~(0xFF << _BIT_SHIFT(IRQn))) |
(((priority << (8 - __NVIC_PRIO_BITS)) & 0xFF) << _BIT_SHIFT(IRQn)); }
}
关于priority值的定义没有注释。