Sound warning circuit for PCI hot plug

摘要

A sound warning circuit for PCI hot plug basically comprises: a timer that takes as inputs a fixed frequency clock and the system port B's bit 0, and which controls the system; a logic AND gate that takes as inputs the timer output and the system port B's bit 1; a speaker driver that takes as an input the AND gate's output; and a speaker that operates based on the speaker driver. In a further embodiment, the timer takes as inputs a fixed frequency clock and either the system port B's bit 0 or a PCI card VDD input, while the AND gate takes as inputs the timer output and any one or more of the system port B's bit 1, a chassis ground cable 0 input, and a chassis ground cable 1 input. In a further embodiment, the AND gate takes as inputs the timer output and either the system port B's bit 1 input or the output of a D Flip-Flop, the latter having the chassis ground cable signal as an input and receiving a reset signal from an AND gate, the latter having as inputs a reset switch input and a system reset # input.