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

`include "opcodes.v"
`ifdef prog_file
  // already defined - do nothing
`else
  `define prog_file  "program.hex"
`endif
`timescale 1ns / 100ps

module program();

reg [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