//------------------------------------------- cputop.v ????? -----------------------------------------------------
/***********************************************************************
***  ?????cputop ????????????????cpu???????????
***                    ???????????????????????????????
***            ??????????????????????CPU????RTL??
***            ?????????????? 
************************************************************************/
`include "ram.v"
`include "rom.v"
`include "addr_decode.v"
`include "cpu.v"

`timescale 1ns / 100ps
`define PERIOD 100             // matches clk_gen.v
module cputop;
  reg reset_req,clock;
  integer test;
  reg [(3*8):0] mnemonic;    //array that holds 3 8-bit ASCII characters
  reg [12:0] PC_addr,IR_addr;
  wire [7:0] data;
  wire [12:0] addr;
  wire rd,wr,halt,ram_sel,rom_sel;

//------------------------   cpu ?????????ROM?RAM?????--------------------------------------
cpu   t_cpu (.clk(clock),.reset(reset_req),.halt(halt),.rd(rd),
                                       .wr(wr),.addr(addr),.data(data));

ram   t_ram  (.addr(addr[9:0]),.read(rd),.write(wr),.ena(ram_sel),.data(data));

rom   t_rom  (.addr(addr),.read(rd),.ena(rom_sel),.data(data));

addr_decode   t_addr_decode (.addr(addr),.ram_sel(ram_sel),.rom_sel(rom_sel));

//--------------------cpu ?????????ROM?RAM???????---------------------------------- 
initial
  begin 
    clock=1;
    //display time in nanoseconds
    $timeformat ( -9,  1, " ns", 12);
    display_debug_message;
    sys_reset;
    test1;
    $stop;
    test2;
    $stop;
    test3;
    $stop;
end
  task display_debug_message;
    begin
      $display("\n**************************************************");
         $display("*  THE FOLLOWING DEBUG TASK ARE AVAILABLE:           *");
         $display("* \"test1; \" to load the 1st diagnostic progran. *");
         $display("*  \"test2; \" to load the 2nd diagnostic program. *");
         $display("*  \"test3; \" to load the Fibonacci program.      *");
         $display("*****************************************************\n");
    end
  endtask
   task test1;
    begin
      test = 0;
      disable MONITOR;
      $readmemb ("test1.pro", t_rom.memory);
      $display("rom loaded   successfully!");
      $readmemb("test1.dat",t_ram.ram);
      $display("ram loaded   successfully!");
      #1 test = 1;
      #14800  ;
      sys_reset;
    end
   endtask
  
  task test2;
    begin
      test = 0;
      disable MONITOR;
      $readmemb("test2.pro",t_rom.memory);
      $display("rom loaded  successfully!");
      $readmemb("test2.dat",t_ram.ram);
      $display("ram loaded  successfully!");
      #1 test = 2;
      #11600;
      sys_reset;
    end
   endtask
  
  task test3;
    begin
      test = 0;
      disable MONITOR;
      $readmemb("test3.pro",t_rom.memory);
      $display("rom loaded  successfully!");
      $readmemb("test3.dat",t_ram.ram);
      $display("ram loaded  successfully!");
      #1 test = 3;
      #94000;
      sys_reset;
    end
   endtask
  
   
  task sys_reset;
    begin
      reset_req = 0;
      #(`PERIOD*0.7) reset_req = 1; 
      #(1.5*`PERIOD) reset_req = 0;  
    end
  endtask 

   always @(test)
    begin: MONITOR
      case (test)
       1: begin                        //display results when running test 1
            $display("\n*** RUNNING CPUtest1 - The Basic CPU Diagnostic Program ***");
            $display("\n     TIME           PC       INSTR      ADDR     DATA  ");
            $display("    ----------      ----     -----     -----       ----- ");
             while (test == 1) 
                  @(t_cpu.m_adr.pc_addr)//fixed
                  if ((t_cpu.m_adr.pc_addr%2 == 1)&&(t_cpu.m_adr.fetch == 1))//fixed 
                begin
                  # 60    PC_addr <=t_cpu.m_adr.pc_addr -1 ;
                          IR_addr <=t_cpu.m_adr.ir_addr;
                 # 340   $strobe("%t   %h     %s     %h  %h", $time, PC_addr, 
                                  mnemonic, IR_addr,data );
                      //HERE DATA HAS BEEN CHANGED T-CPU-M-REGISTER.DATA
               end  
 
           end
           
        2: begin
	     $display("\n*** RUNNING CPUtest2 - The Advanced CPU Diagnostic Program ***");
             $display("\n     TIME          PC       INSTR      ADDR     DATA  ");
             $display("   ----------      ---        -----       -----    ---- ");
             while (test == 2) 
               @(t_cpu.m_adr.pc_addr)
               if ((t_cpu.m_adr.pc_addr%2 == 1) 
                                    && (t_cpu.m_adr.fetch == 1))
               begin 
                # 60    PC_addr  <= t_cpu.m_adr.pc_addr - 1 ;
                        IR_addr  <= t_cpu.m_adr.ir_addr;
                # 340   $strobe("%t  %h  %s  %h %h", $time, PC_addr,
                                               mnemonic, IR_addr, data );
               end  
       
           end
        
        3: begin
             $display("\n***   RUNNING CPUtest3 - An Executable Program   ***");  
             $display("*** This program should calculate the fibonacci  ***");
             $display("\n    TIME      FIBONACCI NUMBER");
             $display(  "  ---------   -----------------");
             while (test == 3)
              begin 
                 wait ( t_cpu.m_alu.opcode == 3'h1) // display Fib. No. at end of program loop
                 $strobe("%t     %d", $time,t_ram.ram[10'h2]);
                 wait ( t_cpu.m_alu.opcode != 3'h1);
              end
           end       
      endcase
      
     end
//-------------------------------------------------------------------------
always @(posedge halt)       //STOP when HALT instruction decoded
    begin
      #500                
          $display("\n*********************************************");
            $display(    "**  A HALT INSTRUCTION WAS PROCESSED  !!!  **");
           $display(     "*********************************************\n");
    end
always #(`PERIOD/2) clock=~clock;   
always  @(t_cpu.m_alu.opcode)  
      //get an ASCII mnemonic for each opcode
    case(t_cpu.m_alu.opcode)
     3'b000  : mnemonic ="HLT";
     3'h1    : mnemonic = "SKZ";
     3'h2    : mnemonic = "ADD";
     3'h3    : mnemonic = "AND";
     3'h4    : mnemonic = "XOR";
     3'h5    : mnemonic = "LDA";
     3'h6    : mnemonic = "STO";
     3'h7    : mnemonic = "JMP";
     default : mnemonic = "???";
    endcase

endmodule
//------------------------------------------- cputop.v ????? -----------------------------------------------------