卡式计费电话电路,用verilogHDL编写,主要完成模拟真实电话的功能-card billing telephone circuits, verilogHDL prepared with the major simulate the real phone function

有关VHDL编程的大量例子，很实用的，自动饮料机，电话计费卡等等，很多。-VHDL programming on the large number of examples, very practical, automatic beverage machine, telephone billing card, etc., many.

本程序是实现在用电话卡打电话时进行自动计费的功能，包括检测通话的种类，时间和余额检测等多项功能，此代码用veriloghdl编写已经调试通过编译。-Implementation of this procedure is used when the phone card to call the function of automatic billing, including the detection of the types of calls, time and number of functi

电话计费器程序，显示卡内余额， 显示本次通话的时长；余额过少时的告警信号。当告警时间过长时自动切断通话信号。-Telephone billing program, showing the balance of the card, the time of the call balance too came from the alarm signal. Automatically when the alarm time is too long to cut off the call signal.