软件如何与硬件交互

[dracularking]

最近突然想到这个问题，计算机的计算能力构建于与或非等组合的逻辑电路晶体管上，它们接受的是高低电平信号，也就是物理触发的，但是一个运行中的程序是如何最终触发物理信号的呢？

我了解到有中断控制器能接收中断消息

Various hardware events—such as a keystroke, mouse click, data coming
through a serial or parallel port, or some software events that need an immediate
response from the processor—generate a special type of signal called an interrupt. As its name implies, an interrupt causes the operating system to temporarily stop what it is doing to divert its attention to the service required by the signal.

但是对于鼠标键盘等物理外设触发的消息可以理解，但是对于无物理外设触发的消息不能理解，比如由串口和并口过来的数据，它最终是怎么生成物理信号的呢？

[dracularking]

顶~等待有缘人~