`include "./alu_basic/alu_basic.v"

module basic_alu_tb;
    reg [15:0] a, b;
    reg [3:0] opcode;

    wire  [15:0] result;
    wire zero, carry, negative;

    basic_alu alu(
        .opcode(opcode),
        .a(a),
        .b(b),
        .result(result),
        .zero(zero),
        .carry(carry),
        .negative(negative)
    );

    initial begin
        $dumpfile("./alu_basic/alu_basic.vcd");
        $dumpvars(0, basic_alu_tb);

        opcode = 4'h0; a = 20; b = 5;
        #1
        $display("opcode=%d, a=%d, b=%d, result=%d, zero=%b, carry=%b, negative=%b", opcode, a, b, result, zero, carry, negative);
        opcode = 4'h1; a = 20; b = 5;
        #1
        $display("opcode=%d, a=%d, b=%d, result=%d, zero=%b, carry=%b, negative=%b", opcode, a, b, result, zero, carry, negative);

        // ADD con overflow: 65535 + 1 = 0, carry=1, zero=1
        opcode = 4'h0; a = 16'hFFFF; b = 1;
        #1
        $display("opcode=%d, a=%d, b=%d, result=%d, zero=%b, carry=%b, negative=%b", opcode, a, b, result, zero, carry, negative);

        // SUB con negativo: 5 - 20, negative=1
        opcode = 4'h1; a = 5; b = 20;
        #1
        $display("opcode=%d, a=%d, b=%d, result=%d, zero=%b, carry=%b, negative=%b", opcode, a, b, result, zero, carry, negative);

        // MUL: 100 * 5 = 500
        opcode = 4'h2; a = 100; b = 5;
        #1
        $display("opcode=%d, a=%d, b=%d, result=%d, zero=%b, carry=%b, negative=%b", opcode, a, b, result, zero, carry, negative);

        // DIV: 100 / 5 = 20
        opcode = 4'h3; a = 100; b = 5;
        #1
        $display("opcode=%d, a=%d, b=%d, result=%d, zero=%b, carry=%b, negative=%b", opcode, a, b, result, zero, carry, negative);

        // AND: 0xFF00 & 0x0FF0 = 0x0F00
        opcode = 4'h4; a = 16'hFF00; b = 16'h0FF0;
        #1
        $display("opcode=%h, a=%h, b=%h, result=%h, zero=%b, carry=%b, negative=%b", opcode, a, b, result, zero, carry, negative);

        // OR: 0xFF00 | 0x0FF0 = 0xFFF0
        opcode = 4'h5; a = 16'hFF00; b = 16'h0FF0;
        #1
        $display("opcode=%h, a=%h, b=%h, result=%h, zero=%b, carry=%b, negative=%b", opcode, a, b, result, zero, carry, negative);

        // NOT: ~0 = 65535
        opcode = 4'h6; a = 0; b = 0;
        #1
        $display("opcode=%d, a=%d, b=%d, result=%d, zero=%b, carry=%b, negative=%b", opcode, a, b, result, zero, carry, negative);

        // XOR: 0xFF00 ^ 0x0FF0 = 0xF0F0
        opcode = 4'h9; a = 16'hFF00; b = 16'h0FF0;
        #1
        $display("opcode=%h, a=%h, b=%h, result=%h, zero=%b, carry=%b, negative=%b", opcode, a, b, result, zero, carry, negative);

        // NEG: -1 en complemento a 2 = 65535
        opcode = 4'hB; a = 1; b = 0;
        #1
        $display("opcode=%d, a=%d, b=%d, result=%d, zero=%b, carry=%b, negative=%b", opcode, a, b, result, zero, carry, negative);
    end

endmodule