// alu8_grader_tb.v

// ALU testbench

// ------------------------------------------------------------------
// Copyright (c) 2007 Susan Lysecky, University of Arizona
// Permission to copy is granted provided that this header remains
// intact. This software is provided with no warranties.
// ------------------------------------------------------------------
`timescale 1ns / 1ps

module Testbench2;
// ---------------------------------------------------------------------------
// ALU test module
// ---------------------------------------------------------------------------

   reg [7:0] A_t, B_t;
   reg x_t, y_t, z_t;
   wire [7:0] Result_t;
   wire Overflow_t;

   ALU8_struct ALU8_struct_1(A_t, B_t, x_t, y_t, z_t, Overflow_t, Result_t);

   initial
   begin
		
      // ----------------------------------------------
      //case xyz = 000, Result = A
	   // ----------------------------------------------
      x_t <= 0; y_t <= 0; z_t <= 0;

      A_t <= 8'b00000000; B_t <= 8'b00000000;
      #1 if (Result_t != 8'b00000000) $display("Error: xyz = %b%b%b, Case 1", x_t, y_t, z_t);
      if (Overflow_t != 0) $display("Overflow Error: Case xyz = %b%b%b, Case 1", x_t, y_t, z_t);

      A_t <= 8'b11110000; B_t <= 8'b00001111;
      #1 if (Result_t != 8'b11110000) $display("Error: xyz = %b%b%b, Case 2", x_t, y_t, z_t);
      if (Overflow_t != 0) $display("Overflow Error: Case xyz = %b%b%b, Case 2", x_t, y_t, z_t);

      A_t <= 8'b11111111; B_t <= 8'b00000000;
      #1 if (Result_t != 8'b11111111) $display("Error: xyz = %b%b%b, Case 3", x_t, y_t, z_t);
      if (Overflow_t != 0) $display("Overflow Error: Case xyz = %b%b%b, Case 3", x_t, y_t, z_t);

      A_t <= 8'b11111111; B_t <= 8'b11111111;
      #1 if (Result_t != 8'b11111111) $display("Error: xyz = %b%b%b, Case 4", x_t, y_t, z_t);
      if (Overflow_t != 0) $display("Overflow Error: Case xyz = %b%b%b, Case 4", x_t, y_t, z_t);


	   // ----------------------------------------------
      //case xyz = 001, Result = B
	   // ----------------------------------------------
      x_t <= 0; y_t <= 0; z_t <= 1;

      A_t <= 8'b00000000; B_t <= 8'b00000000;
      #1 if (Result_t != 8'b00000000) $display("Error: xyz = %b%b%b, Case 1", x_t, y_t, z_t);
      if (Overflow_t != 0) $display("Overflow Error: Case xyz = %b%b%b, Case 1", x_t, y_t, z_t);

      A_t <= 8'b11110000; B_t <= 8'b01001111;
      #1 if (Result_t != 8'b01001111) $display("Error: xyz = %b%b%b, Case 2", x_t, y_t, z_t);
      if (Overflow_t != 0) $display("Overflow Error: Case xyz = %b%b%b, Case 2", x_t, y_t, z_t);

      A_t <= 8'b11111111; B_t <= 8'b11110000;
      #1 if (Result_t != 8'b11110000) $display("Error: xyz = %b%b%b, Case 3", x_t, y_t, z_t);
      if (Overflow_t != 0) $display("Overflow Error: Case xyz = %b%b%b, Case 3", x_t, y_t, z_t);

      A_t <= 8'b11001111; B_t <= 8'b11111111;
      #1 if (Result_t != 8'b11111111) $display("Error: xyz = %b%b%b, Case 4", x_t, y_t, z_t);
      if (Overflow_t != 0) $display("Overflow Error: Case xyz = %b%b%b, Case 4", x_t, y_t, z_t);


	   // ----------------------------------------------
      //case xyz = 010, Result = A + B
	   // ----------------------------------------------
      x_t <= 0; y_t <= 1; z_t <= 0;

      A_t <= 8'b00000000; B_t <= 8'b00000000;
      #1 if (Result_t != 8'b00000000) $display("Error: Case xyz = %b%b%b, Case 1", x_t, y_t, z_t);
      if (Overflow_t != 0) $display("Overflow Error: Case xyz = %b%b%b, Case 1", x_t, y_t, z_t);

      A_t <= 8'b00000110; B_t <= 8'b00000100;
      #1 if (Result_t != 8'b00001010) $display("Error: Case xyz = %b%b%b, Case 2", x_t, y_t, z_t);
      if (Overflow_t != 0) $display("Overflow Error: Case xyz = %b%b%b, Case 2", x_t, y_t, z_t);

      A_t <= 8'b00000001; B_t <= 8'b00001111;
      #1 if (Result_t != 8'b00010000) $display("Error: Case xyz = %b%b%b, Case 3", x_t, y_t, z_t);
      if (Overflow_t != 0) $display("Overflow Error: Case xyz = %b%b%b, Case 4", x_t, y_t, z_t);

      A_t <= 8'b00110000; B_t <= 8'b00010000;
      #1 if (Result_t != 8'b01000000) $display("Error: Case xyz = %b%b%b, Case 4", x_t, y_t, z_t);
      if (Overflow_t != 0) $display("Overflow Error: Case xyz = %b%b%b, Case 4", x_t, y_t, z_t);

      A_t <= 8'b00010001; B_t <= 8'b00010001;
      #1 if (Result_t != 8'b00100010) $display("Error: Case xyz = %b%b%b, Case 5", x_t, y_t, z_t);
      if (Overflow_t != 0) $display("Overflow Error: Case xyz = %b%b%b, Case 5", x_t, y_t, z_t);

      A_t <= 8'b01111111; B_t <= 8'b00000001;
      #1 if (Result_t != 8'b10000000) $display("Error: Case xyz = %b%b%b, Case 6", x_t, y_t, z_t);
      if (Overflow_t != 1) $display("Overflow Error: Case xyz = %b%b%b, Case 6", x_t, y_t, z_t);

      A_t <= 8'b11111100; B_t <= 8'b11111011;
      #1 if (Result_t != 8'b11110111) $display("Error: Case xyz = %b%b%b, Case 7", x_t, y_t, z_t);
      if (Overflow_t != 0) $display("Overflow Error: Case xyz = %b%b%b, Case 7", x_t, y_t, z_t);

      A_t <= 8'b10010000; B_t <= 8'b00010000;
      #1 if (Result_t != 8'b10100000) $display("Error: Case xyz = %b%b%b, Case 8", x_t, y_t, z_t);
      if (Overflow_t != 0) $display("Overflow Error: Case xyz = %b%b%b, Case 8", x_t, y_t, z_t);

      A_t <= 8'b10011100; B_t <= 8'b11001110;
      #1 if (Result_t != 8'b01101010) $display("Error: Case xyz = %b%b%b, Case 9", x_t, y_t, z_t);
      if (Overflow_t != 1) $display("Overflow Error: Case xyz = %b%b%b, Case 9", x_t, y_t, z_t);

      A_t <= 8'b11111111; B_t <= 8'b11111111;
      #1 if (Result_t != 8'b11111110) $display("Error: Case xyz = %b%b%b, Case 10", x_t, y_t, z_t);
      if (Overflow_t != 0) $display("Overflow Error: Case xyz = %b%b%b, Case 10", x_t, y_t, z_t);


   	// ----------------------------------------------
      //case xyz = 011, Result = A - B
	   // ----------------------------------------------
      x_t <= 0; y_t <= 1; z_t <= 1;

      A_t <= 8'b00000000; B_t <= 8'b00000000;
      #1 if (Result_t != 8'b00000000) $display("Case xyz = %b%b%b, Case 1", x_t, y_t, z_t);
      if (Overflow_t != 0) $display("Overflow Error: Case xyz = %b%b%b, Case 1", x_t, y_t, z_t);

      A_t <= 8'b11111111; B_t <= 8'b11111111;
      #1 if (Result_t != 8'b0000) $display("Case xyz = %b%b%b, Case 2", x_t, y_t, z_t);
      if (Overflow_t != 0) $display("Overflow Error: Case xyz = %b%b%b, Case 2", x_t, y_t, z_t);

      A_t <= 8'b00000111; B_t <= 8'b00000010;
      #1 if (Result_t != 8'b00000101) $display("Case xyz = %b%b%b, Case 3", x_t, y_t, z_t);
      if (Overflow_t != 0) $display("Overflow Error: Case xyz = %b%b%b, Case 3", x_t, y_t, z_t);

      A_t <= 8'b00010001; B_t <= 8'b00000100;
      #1 if (Result_t != 8'b00001101) $display("Case xyz = %b%b%b, Case 4", x_t, y_t, z_t);
      if (Overflow_t != 0) $display("Overflow Error: Case xyz = %b%b%b, Case 4", x_t, y_t, z_t);

      A_t <= 8'b11100111; B_t <= 8'b11111011;
      #1 if (Result_t != 8'b11101100) $display("Case xyz = %b%b%b, Case 5", x_t, y_t, z_t);
      if (Overflow_t != 0) $display("Overflow Error: Case xyz = %b%b%b, Case 5", x_t, y_t, z_t);

      A_t <= 8'b11011000; B_t <= 8'b11001110;
      #1 if (Result_t != 8'b00001010) $display("Case xyz = %b%b%b, Case 6", x_t, y_t, z_t);
      if (Overflow_t != 0) $display("Overflow Error: Case xyz = %b%b%b, Case 6", x_t, y_t, z_t);

      A_t <= 8'b00001010; B_t <= 8'b00110010;
      #1 if (Result_t != 8'b11011000) $display("Case xyz = %b%b%b, Case 7", x_t, y_t, z_t);
      if (Overflow_t != 0) $display("Overflow Error: Case xyz = %b%b%b, Case 7", x_t, y_t, z_t);

      A_t <= 8'b01111100; B_t <= 8'b11110000;
      #1 if (Result_t != 8'b10001100) $display("Case xyz = %b%b%b, Case 8", x_t, y_t, z_t);
      if (Overflow_t != 1) $display("Overflow Error: Case xyz = %b%b%b, Case 8", x_t, y_t, z_t);

      A_t <= 8'b00110001; B_t <= 8'b11111101;
      #1 if (Result_t != 8'b00110100) $display("Case xyz = %b%b%b, Case 9", x_t, y_t, z_t);
      if (Overflow_t != 0) $display("Overflow Error: Case xyz = %b%b%b, Case 9", x_t, y_t, z_t);

      A_t <= 8'b10000000; B_t <= 8'b00001010;
      #1 if (Result_t != 8'b01110110) $display("Case xyz = %b%b%b, Case 10", x_t, y_t, z_t);
      if (Overflow_t != 1) $display("Overflow Error: Case xyz = %b%b%b, Case 10", x_t, y_t, z_t);


	   // ----------------------------------------------
      //case xyz = 100, Result = A + 1
	   // ----------------------------------------------
      x_t <= 1; y_t <= 0; z_t <= 0;
		
      A_t <= 8'b00000000; B_t <= 8'b00000000;
      #1 if (Result_t != 8'b00000001) $display("Error: Case xyz = %b%b%b, Case 1", x_t, y_t, z_t);
      if (Overflow_t != 0) $display("Overflow Error: Case xyz = %b%b%b, Case 1", x_t, y_t, z_t);

      A_t <= 8'b11111111; B_t <= 8'b11111111;
      #1 if (Result_t != 8'b00000000) $display("Error: Case xyz = %b%b%b, Case 2", x_t, y_t, z_t);
      if (Overflow_t != 0) $display("Overflow Error: Case xyz = %b%b%b, Case 2", x_t, y_t, z_t);

      A_t <= 8'b00000110; B_t <= 8'b00000001;
      #1 if (Result_t != 8'b00000111) $display("Error: Case xyz = %b%b%b, Case 3", x_t, y_t, z_t);
      if (Overflow_t != 0) $display("Overflow Error: Case xyz = %b%b%b, Case 3", x_t, y_t, z_t);

      A_t <= 8'b00001111; B_t <= 8'b00000001;
      #1 if (Result_t != 8'b00010000) $display("Error: Case xyz = %b%b%b, Case 4", x_t, y_t, z_t);
      if (Overflow_t != 0) $display("Overflow Error: Case xyz = %b%b%b, Case 4", x_t, y_t, z_t);

      A_t <= 8'b01111111; B_t <= 8'b00111100;
      #1 if (Result_t != 8'b10000000) $display("Error: Case xyz = %b%b%b, Case 5", x_t, y_t, z_t);
      if (Overflow_t != 1) $display("Overflow Error: Case xyz = %b%b%b, Case 5", x_t, y_t, z_t);

      A_t <= 8'b10100111; B_t <= 8'b11001100;
      #1 if (Result_t != 8'b10101000) $display("Error: Case xyz = %b%b%b, Case 6", x_t, y_t, z_t);
      if (Overflow_t != 0) $display("Overflow Error: Case xyz = %b%b%b, Case 6", x_t, y_t, z_t);


	   // ----------------------------------------------
      //case xyz = 101, Result = A'
	   // ----------------------------------------------
      x_t <= 1; y_t <= 0; z_t <= 1;

      A_t <= 8'b00000000; B_t <= 8'b00000000;
      #1 if (Result_t != 8'b11111111) $display("Error: Case xyz = %b%b%b, Case 1", x_t, y_t, z_t);
      if (Overflow_t != 0) $display("Overflow Error: Case xyz = %b%b%b, Case 1", x_t, y_t, z_t);

      A_t <= 8'b11111111; B_t <= 8'b11100001;
      #1 if (Result_t != 8'b00000000) $display("Error: Case xyz = %b%b%b, Case 2", x_t, y_t, z_t);
      if (Overflow_t != 0) $display("Overflow Error: Case xyz = %b%b%b, Case 2", x_t, y_t, z_t);

      A_t <= 8'b01101111; B_t <= 8'b01010000;
      #1 if (Result_t != 8'b10010000) $display("Error: Case xyz = %b%b%b, Case 3", x_t, y_t, z_t);
      if (Overflow_t != 0) $display("Overflow Error: Case xyz = %b%b%b, Case 3", x_t, y_t, z_t);

      A_t <= 8'b11001100; B_t <= 8'b01100110;
      #1 if (Result_t != 8'b00110011) $display("xyz = %b%b%b, Case 4", x_t, y_t, z_t);
      if (Overflow_t != 0) $display("Overflow Error: Case xyz = %b%b%b, Case 4", x_t, y_t, z_t);


	   // ----------------------------------------------
      //case xyz = 110, Result = A AND B
	   // ----------------------------------------------
      x_t <= 1; y_t <= 1; z_t <= 0;

      A_t <= 8'b00000000; B_t <= 8'b00000000;
      #1 if (Result_t != 8'b00000000) $display("Error: Case xyz = %b%b%b, Case 1", x_t, y_t, z_t);
      if (Overflow_t != 0) $display("Overflow Error: Case xyz = %b%b%b, Case 1", x_t, y_t, z_t);

      A_t <= 8'b00000000; B_t <= 8'b00001111;
      #1 if (Result_t != 8'b00000000) $display("Error: Case xyz = %b%b%b, Case 2", x_t, y_t, z_t);
      if (Overflow_t != 0) $display("Overflow Error: Case xyz = %b%b%b, Case 2", x_t, y_t, z_t);

      A_t <= 8'b00000110; B_t <= 8'b00000010;
      #1 if (Result_t != 8'b00000010) $display("Error: Case xyz = %b%b%b, Case 3", x_t, y_t, z_t);
      if (Overflow_t != 0) $display("Overflow Error: Case xyz = %b%b%b, Case 3", x_t, y_t, z_t);

      A_t <= 8'b00001010; B_t <= 8'b00001111;
      #1 if (Result_t != 8'b00001010) $display("Error: Case xyz = %b%b%b, Case 4", x_t, y_t, z_t);
      if (Overflow_t != 0) $display("Overflow Error: Case xyz = %b%b%b, Case 4", x_t, y_t, z_t);

      A_t <= 8'b10011001; B_t <= 8'b11110000;
      #1 if (Result_t != 8'b10010000) $display("Error: Case xyz = %b%b%b, Case 5", x_t, y_t, z_t);
      if (Overflow_t != 0) $display("Overflow Error: Case xyz = %b%b%b, Case 5", x_t, y_t, z_t);

      A_t <= 8'b11110000; B_t <= 8'b10001101;
      #1 if (Result_t != 8'b10000000) $display("Error: Case xyz = %b%b%b, Case 6", x_t, y_t, z_t);
      if (Overflow_t != 0) $display("Overflow Error: Case xyz = %b%b%b, Case 6", x_t, y_t, z_t);

      A_t <= 8'b11111111; B_t <= 8'b11111111;
      #1 if (Result_t != 8'b11111111) $display("Error: Case xyz = %b%b%b, Case 7", x_t, y_t, z_t);
      if (Overflow_t != 0) $display("Overflow Error: Case xyz = %b%b%b, Case 7", x_t, y_t, z_t);


	   // ----------------------------------------------
      //case xyz = 111, Result = A OR B
	   // ----------------------------------------------
      x_t <= 1; y_t <= 1; z_t <= 1;
		
		
      A_t <= 8'b00000000; B_t <= 8'b00000000;
      #1 if (Result_t != 8'b00000000) $display("Error: Case xyz = %b%b%b, Case 1", x_t, y_t, z_t);
      if (Overflow_t != 0) $display("Overflow Error: Case xyz = %b%b%b, Case 1", x_t, y_t, z_t);

      A_t <= 8'b00000000; B_t <= 8'b00001111;
      #1 if (Result_t != 8'b00001111) $display("Error: Case xyz = %b%b%b, Case 2", x_t, y_t, z_t);
      if (Overflow_t != 0) $display("Overflow Error: Case xyz = %b%b%b, Case 2", x_t, y_t, z_t);

      A_t <= 8'b00000110; B_t <= 8'b00000010;
      #1 if (Result_t != 8'b00000110) $display("Error: Case xyz = %b%b%b, Case 3", x_t, y_t, z_t);
      if (Overflow_t != 0) $display("Overflow Error: Case xyz = %b%b%b, Case 3", x_t, y_t, z_t);

      A_t <= 8'b10101010; B_t <= 8'b00001111;
      #1 if (Result_t != 8'b10101111) $display("Error: Case xyz = %b%b%b, Case 4", x_t, y_t, z_t);
      if (Overflow_t != 0) $display("Overflow Error: Case xyz = %b%b%b, Case 4", x_t, y_t, z_t);

      A_t <= 8'b11110000; B_t <= 8'b10100000;
      #1 if (Result_t != 8'b11110000) $display("Error: Case xyz = %b%b%b, Case 5", x_t, y_t, z_t);
      if (Overflow_t != 0) $display("Overflow Error: Case xyz = %b%b%b, Case 5", x_t, y_t, z_t);

      A_t <= 8'b11111111; B_t <= 8'b11111111;
      #1 if (Result_t != 8'b11111111) $display("Error: Case xyz = %b%b%b, Case 6", x_t, y_t, z_t);
      if (Overflow_t != 0) $display("Overflow Error: Case xyz = %b%b%b, Case 6", x_t, y_t, z_t);

   end

endmodule