步骤5。用户代码，中断使能。

Step 5. User specific code, enable interrupts.

youdao

如果在响应低优先级中断时高优先级中断使能，用户必须在低优先级中断响应程序中保存那些关键的寄存器值。

If high priority interrupts are not disabled during low priority interrupts, users must save the key registers in software during a low priority interrupt.

youdao

该函数初始化硬件中断和内核，使设备驱动注册事件并使能中断。

This function initializes a hardware interrupt with the kernel. This initialization enables the device driver to register an event and enable the interrupt.

youdao