//Template
//Copy this template and name it "hw3.v".

// Problem 1:
// Write down your name and your  account  here
// Your Name :  #######
// Your Account: #######
//
//Problem 2:
//Look at the memory module and answer
//The memory unit contains data and operators in ASCII format.
// What will be the equation?
//Answer : ########
//(hint:   something like 1+2 + 3 =)
// 
//Problem 3:
//What will be the bit sequence after clock 0
//from memory_read_s module ?
//Just answer first 8-bits.
//Answer:###########
//(hint: 51  = 00110011)
//(hint: Does it provide MSB  for the first bit?      
//(so the answer will be either 00110011 or 11001100)
module memory();
      reg [7:0] mem [7:0];
      initial
      begin
      mem[0] = 3+48;//51 ascii code for 3
      mem[1] = 43;  //43 ascii code for +
      mem[2] = 4+48;//52 ascii code for 4
      mem[3] = 43;  //43 ascii code for +  // ascii code for - is 45
      mem[4] = 5+48;//53 ascii code for 5
      mem[5] = 61;  //61 ascii code for =
      mem[6] = 61;
      mem[7] = 61;
      end
   endmodule

//You don¡¯t have to know this.
// This module memory_read_s will read 1bit data from memory. module memory_read_s(v,ck);
      input ck;
      output v;
      reg [7:0] local_v, index;
      reg [2:0] cnt;
      memory m();
      reg  v;
      initial index = 0;
      initial cnt = 0;
      always @(ck)
      begin

          local_v = m.mem[index];

//          $display("v = index[%d]=  %b\n",index,local_v[cnt]);
          v = local_v[cnt];
//       $display("v = %b ",v); 
          cnt = cnt+1;
          if(cnt == 0) begin
                        index = index +1;
        //   $display("v = \n");
                       end 
      end
endmodule
//

//Problem 4  Complete the module so it can perform the required functionality.
//
//
module serial_ascii_adder(result,v,ck);
       input v,ck;
       output result;
       reg[7:0] local_data1,local_data2,result,temp_result;
       // you will save the incoming bit stream into the registers.
       // or you can declare more regs and save the value on them.
       reg[2:0] cnt;
       reg[2:0] operator;//add : 1 
                         //subtract : 2 
                         //no operator received :3        

   
   parameter     op_add = 1;
   parameter     op_sub = 2;


initial operator = 3;       
 initial cnt = 0;
      always @(ck)
      #1
      
     begin
// Write down your code here
// It should contain this  code :      $display("result = %d\n",result);
//And this :                          $stop;
//The code length will be less than 30 lines.
//My code length  is 20 lines. There will be no penalty for a little bit longer code as long as your program  //produces right answer

          








      end




//

endmodule
//



////////////////////////////Do not modify this test_all module////////////////////////////////////////////////////
module test_all();
   integer i,j;
    reg ck;
    wire [3:0] v1;
    wire vs;
    wire same;
    wire [7:0] result;
    
    initial  ck = 0;
    initial begin 
             for(i = 1; i<= 50; i = i+ 1) 
              begin
                 #10;
                 ck = ~ck;
              end
             end
             
    memory_read_s m_r_s(vs,ck);   
    serial_ascii_adder s_a_a(result,vs,ck);
   
    initial

            $monitor($time, "  result = %d",result);


endmodule