利用Verilog语言设计一个PWM控制器，实现：控制器输入时钟1MHz；控制器输出脉冲周期1kHz，脉宽最小调节步长0.1%。(The Verilog language is used to design a PWM controller, which is realized: the controller input clock 1MHz; the controller output pulse cycle 1kHz, and the pulse width minimum adjustment step 0.1%.)