```
assign diff_out1           = diff_in1;
  assign diff_out2           = diff_in2;
  assign diff_out3           = diff_in3;
  assign diff_out4           = diff_in4;


  assign optocoupler_out1    = optocoupler_in1;
  assign optocoupler_out2    = optocoupler_in2;
  assign optocoupler_out3    = optocoupler_in3;
  assign optocoupler_out4    = optocoupler_in4;


  assign uart_tx             = uart_rx;
  assign stm32_output_bus[0] = stm32_input_bus[0];
  assign stm32_output_bus[1] = stm32_input_bus[1];
  assign stm32_output_bus[2] = stm32_input_bus[2];
  assign stm32_output_bus[3] = stm32_input_bus[3];
  assign stm32_output_bus[4] = stm32_input_bus[4];
  assign stm32_output_bus[5] = stm32_input_bus[5];
  assign stm32_output_bus[6] = stm32_input_bus[6];
  assign stm32_output_bus[7] = stm32_input_bus[7];

  FPGA引出的测试引脚分别输出
        pwm100hz
        pwm101hz
        pwm102hz
        pwm103hz
        pwm104hz
        pwm105hz
        pwm106hz
        pwm107hz
        pwm108hz
        pwm109hz
        pwm110hz
        pwm111hz
        pwm112hz
        pwm113hz
        pwm114hz
        pwm115hz

    亮度控制:
      .pwm100hz(lt1_en),
      .pwm101hz(lt2_en),
      .pwm102hz(lt3_en),
      .pwm103hz(lt4_en),
      .pwm104hz(lt1_intensity_ctrl),
      .pwm105hz(lt2_intensity_ctrl),
      .pwm106hz(lt3_intensity_ctrl),
      .pwm107hz(lt4_intensity_ctrl)
   


```