//Testbench for miniCPU

`timescale 10ns/1ns
`include "C:/intelFPGA_lite/23.1std/miniCPU_modules.sv"
//`include "C:/intelFPGA_lite/23.1std/miniCPU_tb_tasks.sv"

module miniCPU_tb;
	
	//Outputs of dut = inputs to testbench
	wire [15:0] 	Address_tb;
	wire		Read_tb;
	wire		Write_tb;
	wire		IO_Req_tb;
	wire		Mem_Req_tb;
	wire [7:0] 	State_tb;
	wire		Dir_tb;
	wire [7:0]	Data_bus_tb;
	
	//Inputs to dut = outputs from testbench
	reg		Reset_tb, Clock_tb;
	
	//Testbench variables
	reg [7:0]	Data_out_tb;
	reg [7:0]	Data_in_tb;
  	logic [7:0]	mem [0:255];
	logic [7:0] 	port [0:15];
	int		fd;
	
	miniCPU dut (
		.Reset(Reset_tb),
		.Address(Address_tb),
		.Data_bus(Data_bus_tb),
		.Clock(Clock_tb),
		.Read(Read_tb),
		.Write(Write_tb),
		.IO_Req(IO_Req_tb),
		.Mem_Req(Mem_Req_tb),
		.State(State_tb),
		.Dir(Dir_tb));

	bidirec2 U1 (Dir_tb, Data_in_tb, Data_out_tb, Data_bus_tb);

	initial
    	begin :initial_block
      		open_file;
      		readBinFile2Mem;
      		close_file;
		printMem;
    	end :initial_block


	initial
	begin: CLOCK_GENERATOR
		Clock_tb=0;
		forever
		begin
		#25 Clock_tb = ~ Clock_tb;
		end
	end

	initial
	begin
		Reset_tb = 0;
		#500 Reset_tb = 1;
	end

	
	always @(*) begin //Read memory
		if (!Mem_Req_tb & !Read_tb) 
		Data_in_tb = mem [Address_tb [7:0]];
	end

	always @(posedge Clock_tb) begin	//Write memory
		if (!Mem_Req_tb & !Write_tb)
		mem [Address_tb [7:0]] <= Data_out_tb;
	end

	always @(*) begin 			//Read port
		if (!IO_Req_tb & !Read_tb) 
		Data_in_tb = port [Address_tb [3:0]];
	end

	always @(posedge Clock_tb) begin	//Write port
		if (!IO_Req_tb & !Write_tb)
		port [Address_tb [3:0]] <= Data_out_tb;
	end



// ---------------------------------------------------------------------------
// Open the file
// ---------------------------------------------------------------------------
  task open_file();
    $display("Opening file");
    fd = $fopen("test1.obj","rb");
    $display ("File descriptor 1 = %0d", fd);
  endtask

  // ---------------------------------------------------------------------------
  // Read the contents of file descriptor
  // ---------------------------------------------------------------------------
  task readBinFile2Mem ();
    int n_Temp;
    n_Temp = $fread(mem, fd);
    $display ("File descriptor 2 = %0d", fd);
    $display("n_Temp = %0d",n_Temp);
  endtask
  
  // ---------------------------------------------------------------------------
  // Close the file
  // ---------------------------------------------------------------------------
  task close_file();
    $display("Closing the file");
    $fclose(fd);
  endtask

// ---------------------------------------------------------------------------
  // Print memory contents
  // ---------------------------------------------------------------------------  
  task printMem();
    foreach(mem[i])
      $display("mem[%0d] = %h",i,mem[i]);
  endtask


endmodule