一个apb总线控制8253的verilog源代码，符合标准的amba 2.0的总线规范-A apb bus control 8253 of the verilog source code, amba 2.0 standard bus specification

采用8253，8255，8259实现交通灯的控制，十字路口，有详细硬件连接图，软件代码以及详细的工作原理-8253,8255,8259 adopted to achieve the control of traffic lights, crossroads, and a detailed plan to connect the hardware, software code, as well as detailed working principle