An ACL packet, which can interrupt the regular flow of SCO data.
为一acl数据包，可中断正常的SCO数据流。
2
Before the interrupt is raised, all other pre-requisites (setting up any address, data, etc.) for that interrupt should be handled in the kernel thread.
在触发中断之前，该中断的所有其他前提条件(设置地址、数据等)都应该在内核线程中进行处理。
3
Interrupt transfers: These are data packets that are polled periodically.