cpu/lib/tb/skidbuffer_tb.sv

`timescale 1ns/1ps

// import bh_assert::*;

module skidbuffer_tb();

int bh_assert_pass_count = 0;
int bh_assert_fail_count = 0;
int bh_assert_warn_count = 0;

localparam BH_ASSERT_LOG_LEVEL_FAIL = 0;
localparam BH_ASSERT_LOG_LEVEL_ASSERT = 1;
localparam BH_ASSERT_LOG_LEVEL_WARN = 2;
localparam BH_ASSERT_LOG_LEVEL_INFO = 3;

logic bh_assert_log_level = BH_ASSERT_LOG_LEVEL_WARN;  // 0 = errors only, 1 = all assertions, 2 = warnings, 3 = info

localparam COLOR_RED = "\033[31m";
localparam COLOR_YELLOW = "\033[33m";
localparam COLOR_GREEN = "\033[32m";
localparam COLOR_NORMAL = "\033[0;39m";

task bh_assert_equal(int val, int expected, string description);
    // display results
    $timeformat(-9, 2, " ns", 20);
    $display(
        "%t: %s: %d %s %d - %s",
        $time,
        val == expected ? {COLOR_GREEN, "PASS", COLOR_NORMAL} : {COLOR_RED, "FAIL", COLOR_NORMAL},
        val,
        val == expected ? "==" : "!=",
        expected,
        description
    );

    // update statistics
    if (val == expected) begin
        bh_assert_pass_count = bh_assert_pass_count + 1;
    end else begin
        bh_assert_fail_count = bh_assert_fail_count + 1;
    end
endtask

task bh_assert_stats;
    $timeformat(-9, 2, " ns", 20);
    $display("%t: DONE: %1d pass, %1d fail, %1d warn", $time, bh_assert_pass_count, bh_assert_fail_count, bh_assert_warn_count);
    if (bh_assert_pass_count + bh_assert_fail_count == 0) begin
        $display("%sERROR%s: no assertions found", COLOR_YELLOW, COLOR_NORMAL);
        // TODO: error in a better way?
    end else if (bh_assert_fail_count > 0) begin
        $display("%sERROR%s: some tests failed", COLOR_RED, COLOR_NORMAL);
    end else begin
        $display("%sSUCCESS%s: all tests passed", COLOR_GREEN, COLOR_NORMAL);
    end
endtask

task bh_info(string description);
    if (bh_assert_log_level >= BH_ASSERT_LOG_LEVEL_INFO) begin
        $display("%t: INFO: %s", $time, description);
    end
endtask

task bh_warn(string description);
    if (bh_assert_log_level >= BH_ASSERT_LOG_LEVEL_WARN) begin
        $display("%t: %sWARN%s: %s", $time, COLOR_YELLOW, COLOR_NORMAL, description);
    end
    bh_assert_warn_count = bh_assert_warn_count + 1;
endtask


parameter WIDTH = 15;
parameter TEST_LIST_LENGTH = 256;

logic clk = 0;
logic reset = 1;
logic [WIDTH-1:0] in;
logic in_valid = 0;
wire in_ready;
wire [WIDTH-1:0] out;
wire out_valid;
logic out_ready = 0;

skidbuffer #(
    .WIDTH(WIDTH)
) dut (
    .clk(clk),
    .reset(reset),
    .in(in),
    .in_valid(in_valid),
    .in_ready(in_ready),
    .out(out),
    .out_valid(out_valid),
    .out_ready(out_ready)
);

integer i = 0;
integer in_count = 0;
integer out_count = 0;
logic [WIDTH-1:0] in_list [0:TEST_LIST_LENGTH-1];

assign in = in_list[in_count];

always #5 clk = !clk;

initial begin
    $dumpfile("skidbuffer_tb.vcd");
    $dumpvars(0, skidbuffer_tb);

    for (i=0; i<TEST_LIST_LENGTH; i=i+1) begin
        in_list[i] = $urandom();
    end

    #10
    reset = 0;

    while (out_count < TEST_LIST_LENGTH) begin
        #10
        if (!in_valid || (in_valid && in_ready)) begin
            in_valid = $urandom_range(1);
        end
        if (!out_ready || (out_ready && out_valid)) begin
            out_ready = $urandom_range(1);
        end
    end

    bh_assert_stats();
    $finish;
end

always @(posedge clk) begin
    if (reset == 0 && in_valid && in_ready) begin
        in_count <= in_count + 1;
    end

    if (reset == 0 && out_valid && out_ready) begin
        bh_assert_equal(out, in_list[out_count], $sformatf("Output value [%3d]", out_count));
        bh_warn("hello warning");
        bh_info("hello info");
        out_count <= out_count + 1;
    end
end

wire [WIDTH-1:0] out_correct;
assign out_correct = in_list[out_count];


endmodule