///////////////////////////////////////////////////////////////////////
//
// code_mem module
//     This module is used to perform a simple program assembly
//
//
///////////////////////////////////////////////////////////////////////

`ifdef prog_file
  // already defined - do nothing
`else
  `define prog_file  "program.hex"
`endif

module code_mem();

timeunit 1ns;
timeprecision 100ps;

import definitions::*;

logic [15:0] Data_stored [ 0 : 255 ];

   initial
      begin
         // DATA - variables stored in RAM
         `define VAR_X		12'd256
         `define VAR_Y		12'd257
         // DATA - i/o in i/o module
         `define SWITCHES	12'h800
         `define LEDS		12'h801
         // DATA - constants stored here in rom
         `define CONST_0	12'd20
         `define CONST_1	12'd21
         Data_stored[20] = {16'd0};
         Data_stored[21] = {16'd1};

         // CODE:
         Data_stored[0] = {LDA,`SWITCHES};
         Data_stored[1] = {STA,`VAR_X};

         Data_stored[2] = {SUB,`CONST_1};	// .loop
         Data_stored[3] = {JMPZ,12'd9};	// If Accumulator = 0 then Jump .done
         Data_stored[4] = {STA,`VAR_Y};
         Data_stored[5] = {ADD,`VAR_X};
         Data_stored[6] = {STA,`VAR_X};
         Data_stored[7] = {LDA,`VAR_Y};
         Data_stored[8] = {JMP,12'd2};		// Jump .loop
         Data_stored[9] = {LDA,`VAR_X};	// .done
         Data_stored[10] = {STA,`LEDS};
         Data_stored[11] = {JMP,12'd99};	// Jump .end

         Data_stored[99] = {JMP,12'd99};	// .end

         $writememh( `prog_file, Data_stored );

      end


endmodule