不能指定多个值。

Question

我是Verilog的新手，我试着制作一个CPLD电源的保护逻辑，它实际上使用了一串计时器来验证状态机。我有一个带1兆赫OSC的CPLD，我试着做一个15s定时器，我计算了代码，但是它有编译错误，说“不能被分配超过一个值”。我知道这意味着信号网络是由两个不同的信号控制的，但是它有一个错误行显示。

错误(12014)：Net "Fifty_m_second_Devide_Clock_input"，它支持“计时器”，不能分配多个值错误(12015)：Net由"clk_div:d|clk_out“错误(12015)：Net由"Fifty_m_second_Devide_Clock_input”提供。

why "Fifty_m_second_Devide_Clock_input" is connected to itself??

  module PowerUpProtection(

    //---------------------------------------------------------------------------
    // Inputs
    //---------------------------------------------------------------------------
    input wire Fifty_m_second_Devide_Clock_input,
    input wire Clock,
    input wire Reset,
    input wire Input1_Check_precharge_status,
    input wire Input2_MainPowerSwitch_relay_status_Check,
    input wire Input3_powerUp_validation,

    //---------------------------------------------------------------------------

    //---------------------------------------------------------------------------
    // Outputs
    //---------------------------------------------------------------------------
    output reg Output1_Relay_Swtich_For_Main_PowerSource,
    output reg Output2_Switch_On_and_Charge_CAP,
    output reg Output3_Switch_On_and_power_SoM,
    output reg Output4_Press_and_hold_the_powerSource,
    output reg Output5_Switch_on_relay_when_CPLD_powerup
    //---------------------------------------------------------------------------
    );


    // this is a Module Instantiation, connect the inputs and output from different module within CPLD.
    clk_div d(
        .Clock  (Clock),
        .reset(Reset),
        .clk_out(Fifty_m_second_Devide_Clock_input)
    );
    //---------------------------------------------------------------------------


    //---------------------------------------------------------------------------
    // State Encoding 
    //---------------------------------------------------------------------------
    localparam STATE_0_Initial = 4'd0,
                  STATE_1_Press_and_hold = 4'd1,
                  STATE_2_Power_up = 4'd2,
                  STATE_3_Check_Switches = 4'd3,
                 STATE_4_SwtichSafe_StartPreCharging = 4'd4,
                  STATE_5_ERROR = 4'd5,
                  STATE_6_CAP_is_Charging = 4'd6,
                  STATE_7_Charging_End_SwitchOn_MainPower = 4'd7,
                  STATE_8_PowerSupply_Ready = 4'd8,
                  ERROR_9_TIME_OUT = 4'd9,
                  STATE_10_Precharge_Switch_is_broken = 4'd10,
                  STATE_11_Main_power_switch_is_broken = 4'd11,
                  STATE_12_Both_switches_are_broken = 4'd12,
                  STATE_13_PlaceHolder = 4'd13,
                  STATE_14_PlaceHolder = 4'd14,
                  STATE_15_PlaceHolder = 4'd15;       
    //---------------------------------------------------------------------------



    //---------------------------------------------------------------------------
    // State reg Declarations
    //---------------------------------------------------------------------------
    reg [3:0] CurrentState = 4'd0;
    reg [3:0] NextState = 4'd0;
    //---------------------------------------------------------------------------



    //---------------------------------------------------------------------------
    // Timer reg Declarations
    //---------------------------------------------------------------------------
    reg [8:0] Timer = 0;
    reg enable_the_counter = 0;  // the boolean to enbale the counter.
    reg clear_the_counter = 0;

    //---------------------------------------------------------------------------   

    //---------------------------------------------------------------------------
    // Outputs
    //---------------------------------------------------------------------------   
    always@(*) begin
        // clear for the initial state.
        reg Output1_Relay_Swtich_For_Main_PowerSource = 0;
        reg Output2_Switch_On_and_Charge_CAP = 0;
        reg Output3_Switch_On_and_power_SoM = 0;
        reg Output4_Press_and_hold_the_powerSource = 0;
        reg Output5_Switch_on_relay_when_CPLD_powerup = 0;

        case (CurrentState)
            STATE_1_Press_and_hold : begin
                Output4_Press_and_hold_the_powerSource = 1;
            end

            STATE_2_Power_up        : begin
                Output5_Switch_on_relay_when_CPLD_powerup = 1;
            end

            STATE_3_Check_Switches   : begin
                Output2_Switch_On_and_Charge_CAP = 1;
            end 

            STATE_4_SwtichSafe_StartPreCharging : begin
                Output2_Switch_On_and_Charge_CAP = 1;
            end

            STATE_5_ERROR : begin
                // to be determined
            end

            STATE_6_CAP_is_Charging :  begin 
                // wait for the charging to be complete
            end

            STATE_7_Charging_End_SwitchOn_MainPower : begin
                Output1_Relay_Swtich_For_Main_PowerSource =1;
            end

            STATE_8_PowerSupply_Ready : begin
                Output5_Switch_on_relay_when_CPLD_powerup = 0;
                Output3_Switch_On_and_power_SoM = 1;
            end
        endcase
    end
    //---------------------------------------------------------------------------   



    //---------------------------------------------------------------------------
    // Synchronous State-Transition always@(posedge Clock) block
    //---------------------------------------------------------------------------
    always@(posedge Clock) begin
        if (Reset) CurrentState <= STATE_0_Initial;
        else CurrentState <= NextState;
    end
    //---------------------------------------------------------------------------


    //---------------------------------------------------------------------------
    // conditional State-Trasnsition Always@(*) block
    //---------------------------------------------------------------------------
    always@(*) begin
        NextState = CurrentState;
        case (CurrentState)

            STATE_0_Initial :begin
                NextState = STATE_1_Press_and_hold;
            end

            STATE_1_Press_and_hold : begin
                if (Input3_powerUp_validation) NextState = STATE_2_Power_up;
            end

            STATE_2_Power_up : begin
                if (Input3_powerUp_validation) NextState = STATE_3_Check_Switches;
            end

            STATE_3_Check_Switches : begin 
                if (Input1_Check_precharge_status == 0 && Input2_MainPowerSwitch_relay_status_Check == 1 )
                    begin
                    NextState = STATE_4_SwtichSafe_StartPreCharging;
                    enable_the_counter = 1; //Start to count the time.
                    end

                else if (Input1_Check_precharge_status == 1 && Input2_MainPowerSwitch_relay_status_Check == 1)
                    begin
                    NextState = STATE_10_Precharge_Switch_is_broken;
                    end

                else if (Input1_Check_precharge_status == 0 && Input2_MainPowerSwitch_relay_status_Check == 0)
                    begin
                    NextState = STATE_11_Main_power_switch_is_broken;
                    end

                else
                    begin 
                    NextState = STATE_12_Both_switches_are_broken;
                    end

            end

            STATE_4_SwtichSafe_StartPreCharging : begin

                if (Input1_Check_precharge_status == 1 && Timer <= 300) //equals to 15 seconds
                    NextState = STATE_6_CAP_is_Charging;

                else if (Timer > 300)
                    NextState = STATE_5_ERROR;  //Time out Error
                    clear_the_counter = 1;
                    enable_the_counter = 0;
            end

            STATE_6_CAP_is_Charging : begin

                if (Input1_Check_precharge_status == 0 && Timer <= 300) 
                    begin
                        NextState = STATE_7_Charging_End_SwitchOn_MainPower;
                        clear_the_counter = 1; // timer is over, clear the  counter.
                        enable_the_counter =0;
                    end
                else if (Timer > 300)
                    begin
                        NextState = STATE_5_ERROR;  //Time out Error
                        clear_the_counter = 1;
                        enable_the_counter = 0;
                    end
            end 

            STATE_7_Charging_End_SwitchOn_MainPower : begin

                //enable the counter again, and count for 50 m seconds.
                enable_the_counter = 1;
                if (Input2_MainPowerSwitch_relay_status_Check ==1)
                        begin
                        if (Timer <=1)
                            NextState = STATE_7_Charging_End_SwitchOn_MainPower; // if time is not 50 ms yet, go back to itself current  state
                        else
                            NextState = STATE_5_ERROR;  //Time out Error
                            clear_the_counter = 1;
                            enable_the_counter = 0;
                        end
                else if (Input2_MainPowerSwitch_relay_status_Check == 0)  // if the switch is ready right away, that is best.

                        begin
                        NextState = STATE_8_PowerSupply_Ready; 
                        end
                else 
                        NextState = STATE_5_ERROR;  //Time out Error
                        clear_the_counter = 1;
                        enable_the_counter = 0;
            end

            //---------------------------------------------------------------------------
            // Place-Holder transition.
            //---------------------------------------------------------------------------
            STATE_13_PlaceHolder : begin
                NextState = STATE_5_ERROR;
            end

            STATE_14_PlaceHolder : begin
                NextState = STATE_5_ERROR;
            end
            STATE_15_PlaceHolder : begin
                NextState = STATE_5_ERROR;
            end


        endcase
    end 

    //---------------------------------------------------------------------------
    // 50 m Seconds counter block, make the osc into 20 HZ by implement the counter
    //---------------------------------------------------------------------------

    always@(posedge Fifty_m_second_Devide_Clock_input or posedge Reset or posedge clear_the_counter ) begin
        if (Reset == 1 || clear_the_counter == 1) 
            begin
                Timer = 0;
            end
        else
            begin 
                if (enable_the_counter) 
                Timer <= Timer + 1'b1;
            end
    end
    //---------------------------------------------------------------------------



endmodule





    //clock devider, the board has a 10 M hz osc, 
//so I create this code to count 200000 times 
//for each posedge and that equalle to 50 m-second.
// if count until 50 m-second, this clk_out will output one positive edge.

module clk_div(
    input Clock,
    input reset,
    output reg clk_out
    );
    parameter diver = 99999;
    reg [23:0] count;//just for 99999 or warning

    always@(posedge Clock or posedge reset)
    begin
        if(reset)
        begin
            count <= 0;
            clk_out <= 1'b0;
        end
        else if(count == diver)
        begin
            clk_out <= ~clk_out;
            count <= 0;
        end
        else
        begin
            count <= count + 1'b1;
        end
    end

endmodule

Answer 1

Fifty_m_second_Devide_Clock_input在输入中，这意味着它应该由实例化PowerUpProtection的任何模块来驱动(如果它的顶部模块是某个引脚)，因此它是第一个驱动程序。第二个驱动程序是clk_div模块d。在这里，Fifty_m_second_Devide_Clock_input连接到输出clk_out。

从代码中看，这个信号应该是从时钟分配器中驱动的，所以您可能应该从输入中删除这个信号，并在模块主体中声明它为reg。或者可能屏蔽信号，这样您就可以决定如何驱动它(assign Fifty_m_second_Devide_Clock_input = (mux_Fifty_m_second) ? Fifty_m_second_Devide_Clock_from_inputs : Fifty_m_second_Devide_Clock_from_clk_div;或其他什么)。