电子分频器：有源电路，位于功率放大器之前，将前置音频信号分频后再用各自独立的功率放大器，把每一个音频频段信号给予放大，然后分别送到相应的扬声器单元-Electronic frequency divider: active circuits, in front of the power amplifier, will lead audio signal frequency and then separate the power amplifier, the every audio frequenc

设计一个简单的数字电路用于电子卖报机，要求如下： 报纸价格为1.5元；投币器只接受5角和1元硬币；投币器不找零。当投入金额合适时，报纸出口打开，否则关闭。用Verilog完成设计。(The design of a simple digital circuit for electronic selling machine, the following: The price is 1.5 yuan; the coin only accept 5 cents and $1 coin coin do