`timescale 1ns/1ps

module tb_control;

    localparam int unsigned DAC_DATA_WIDTH = 12;

    //------------------------------------------------------------
    // clocks
    //------------------------------------------------------------
    logic ctrl_clk;
    logic dac_clk_in;
    logic adc_clk_in;

    initial begin
        ctrl_clk = 0;
        forever #4 ctrl_clk = ~ctrl_clk;          //125 MHz
    end

    initial begin
        dac_clk_in = 0;
        forever #3.846 dac_clk_in = ~dac_clk_in;  //~130 MHz
    end

    initial begin
        adc_clk_in = 0;
        forever #7.692 adc_clk_in = ~adc_clk_in;  //~65 MHz
    end

    //------------------------------------------------------------
    // DUT inputs
    //------------------------------------------------------------
    logic rst_n;
    logic rst_soft;

    logic finish;

    logic [127:0] cfg_bus_input;
    logic         cfg_bus_valid;

    logic start;

    //------------------------------------------------------------
    // DUT outputs
    //------------------------------------------------------------
    logic busy;

    logic [31:0] dac_pulse_width;
    logic [31:0] dac_pulse_period;
    logic [DAC_DATA_WIDTH-1:0] dac_pulse_height;
    logic [15:0] dac_pulse_num;

    logic [31:0] adc_pulse_period;
    logic [15:0] adc_pulse_num;

    logic dac_start;
    logic adc_start;

    logic dac_rst;
    logic adc_rst;

    //------------------------------------------------------------
    // DUT
    //------------------------------------------------------------

    control #(
        .DAC_DATA_WIDTH(DAC_DATA_WIDTH)
    ) dut (
        .ctrl_clk(ctrl_clk),
        .dac_clk_in(dac_clk_in),
        .adc_clk_in(adc_clk_in),

        .rst_n(rst_n),
        .rst_soft(rst_soft),

        .finish(finish),

        .cfg_bus_input(cfg_bus_input),
        .cfg_bus_valid(cfg_bus_valid),

        .start(start),

        .busy(busy),

        .dac_pulse_width(dac_pulse_width),
        .dac_pulse_period(dac_pulse_period),
        .dac_pulse_height(dac_pulse_height),
        .dac_pulse_num(dac_pulse_num),

        .adc_pulse_period(adc_pulse_period),
        .adc_pulse_num(adc_pulse_num),

        .dac_start(dac_start),
        .adc_start(adc_start),
        .dac_rst(dac_rst),
        .adc_rst(adc_rst)
    );

    //------------------------------------------------------------
    // pulse counters
    //------------------------------------------------------------

    int dac_start_count;
    int adc_start_count;
    int dac_rst_count;
    int adc_rst_count;

    always_ff @(posedge dac_clk_in) begin
        if (!rst_n) begin
            dac_start_count <= 0;
            dac_rst_count   <= 0;
        end
        else begin
            if (dac_start) dac_start_count++;
            if (dac_rst)   dac_rst_count++;
        end
    end

    always_ff @(posedge adc_clk_in) begin
        if (!rst_n) begin
            adc_start_count <= 0;
            adc_rst_count   <= 0;
        end
        else begin
            if (adc_start) adc_start_count++;
            if (adc_rst)   adc_rst_count++;
        end
    end

    //------------------------------------------------------------
    // tasks
    //------------------------------------------------------------

    task automatic send_cfg(
        input logic [31:0] pulse_width,
        input logic [31:0] pulse_period,
        input logic [15:0] pulse_num,
        input logic [15:0] pulse_height,
        input logic [31:0] adc_period
    );
    begin

        cfg_bus_input = {
            adc_period,
            pulse_height,
            pulse_num,
            pulse_period,
            pulse_width
        };

        @(posedge ctrl_clk);
        cfg_bus_valid <= 1;

        @(posedge ctrl_clk);
        cfg_bus_valid <= 0;

    end
    endtask

    task automatic send_start;
    begin
        @(posedge ctrl_clk);
        start <= 1;

        @(posedge ctrl_clk);
        start <= 0;
    end
    endtask

    task automatic send_soft_reset;
    begin
        @(posedge ctrl_clk);
        rst_soft <= 1;

        @(posedge ctrl_clk);
        rst_soft <= 0;
    end
    endtask

    task automatic pulse_finish;
    begin
        @(posedge adc_clk_in);
        finish <= 1;

        @(posedge adc_clk_in);
        finish <= 0;
    end
    endtask

    //------------------------------------------------------------
    // TEST
    //------------------------------------------------------------

    initial begin

        rst_n         = 0;
        rst_soft      = 0;

        finish        = 0;

        start         = 0;

        cfg_bus_valid = 0;
        cfg_bus_input = 0;

        repeat(10) @(posedge ctrl_clk);

        rst_n = 1;

        repeat(10) @(posedge ctrl_clk);

        //--------------------------------------------------------
        // TEST 1 RESET
        //--------------------------------------------------------

        $display("TEST RESET");

        send_soft_reset();

        repeat(20) @(posedge ctrl_clk);

        assert(dac_rst_count==1);
        assert(adc_rst_count==1);

        //--------------------------------------------------------
        // TEST 2 CONFIG
        //--------------------------------------------------------

        $display("TEST CONFIG");

        send_cfg(
            32'h11223344,
            32'h55667788,
            16'hA1B2,
            16'h0CDE,
            32'h50607080
        );

        repeat(30) @(posedge ctrl_clk);

        assert(dac_pulse_width  == 32'h11223344);
        assert(dac_pulse_period == 32'h55667788);
        assert(dac_pulse_num    == 16'hA1B2);
        assert(dac_pulse_height == 12'hCDE);

        assert(adc_pulse_period == 32'h50607080);
        assert(adc_pulse_num    == 16'hA1B2);

        //--------------------------------------------------------
        // TEST 3 START
        //--------------------------------------------------------

        $display("TEST START");

        send_start();

        repeat(20) @(posedge ctrl_clk);

        assert(busy);

        assert(dac_start_count==1);
        assert(adc_start_count==1);

        //--------------------------------------------------------
        // TEST 4 FINISH
        //--------------------------------------------------------

        $display("TEST FINISH");

        pulse_finish();

        repeat(20) @(posedge ctrl_clk);

        assert(!busy);

        //--------------------------------------------------------
        // TEST 5 START AGAIN
        //--------------------------------------------------------

        send_start();

        repeat(20) @(posedge ctrl_clk);

        assert(dac_start_count==2);
        assert(adc_start_count==2);

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

        $display("");
        $display("==============================");
        $display("ALL TESTS PASSED");
        $display("==============================");

        #100;
        $finish;

    end

endmodule