`include "settings.h"

module ARM
(
  input clk,
  input rst,
  input enableForwarding
);

  wire [`WORD_WIDTH-1:0] IF_stage_pc_out;
  wire [`WORD_WIDTH-1:0] IF_stage_instruction_out;
  wire [`WORD_WIDTH-1:0] branch_address;
  wire EXE_stage_B_out;
  wire hazard_detected;

  IF_Stage  IF_Stage_Inst (
   .clk(clk),
   .rst(rst),
   .freeze(hazard_detected),
   .branch_taken(EXE_stage_B_out),
   .branch_addr(branch_address),
   .pc(IF_stage_pc_out),
   .instruction(IF_stage_instruction_out)
  );

  wire [`WORD_WIDTH-1:0] IF_reg_pc_out;
  wire [`WORD_WIDTH-1:0] IF_reg_instruction_out;

  IF_Reg  IF_Reg_Inst (
   .clk(clk),
   .rst(rst),
   .freeze(hazard_detected),
   .flush(EXE_stage_B_out),
   .pc_in(IF_stage_pc_out),
   .instruction_in(IF_stage_instruction_out),
   .pc(IF_reg_pc_out),
   .instruction(IF_reg_instruction_out)
  );

  wire [`WORD_WIDTH-1:0]              ID_stage_pc_out;
  wire [`WORD_WIDTH-1:0]              ID_stage_instruction_out;
	wire [`REG_FILE_DEPTH-1:0] 				ID_stage_reg_file_dst;
  wire [`REG_FILE_DEPTH-1:0] 				ID_stage_reg_file_src1, ID_stage_reg_file_src2;
	wire [`WORD_WIDTH-1:0] 						ID_stage_val_Rn, ID_stage_val_Rm;
	wire [`SIGNED_IMM_WIDTH-1:0] 			ID_stage_signed_immediate;
	wire [`SHIFTER_OPERAND_WIDTH-1:0] ID_stage_shifter_operand;
	wire [3:0] 												ID_stage_EX_command_out;
	wire [3:0]              status;
	wire ID_stage_mem_read_out, ID_stage_mem_write_out,
		ID_stage_WB_en_out,
		ID_stage_Imm_out,
		ID_stage_B_out,
		ID_stage_SR_update_out;

  wire [`REG_FILE_DEPTH-1:0] WB_Stage_dst_out;
  wire [`WORD_WIDTH-1:0] WB_Value;
  wire WB_Stage_WB_en_out;
  wire has_src2;

  ID_Stage ID_Stage_Inst(
    .clk(clk),
    .rst(rst),
    .freeze(hazard_detected),
    .pc_in(IF_reg_pc_out),
    .instruction_in(IF_reg_instruction_out),
    .reg_file_wb_address(WB_Stage_dst_out),
	  .reg_file_wb_data(WB_Value),
	  .reg_file_enable(WB_Stage_WB_en_out),
    .reg_file_src1(ID_stage_reg_file_src1),
    .reg_file_src2(ID_stage_reg_file_src2),
    .status_register(status),
    .pc(ID_stage_pc_out),
    .instruction(ID_stage_instruction_out),
	  .reg_file_dst(ID_stage_reg_file_dst),
	  .val_Rn(ID_stage_val_Rn), .val_Rm(ID_stage_val_Rm),
	  .signed_immediate(ID_stage_signed_immediate),
	  .shifter_operand(ID_stage_shifter_operand),
	  .EX_command_out(ID_stage_EX_command_out),
	  .mem_read_out(ID_stage_mem_read_out), .mem_write_out(ID_stage_mem_write_out),
		.WB_en_out(ID_stage_WB_en_out),
		.Imm_out(ID_stage_Imm_out),
		.B_out(ID_stage_B_out),
		.SR_update_out(ID_stage_SR_update_out),
		.has_src2(has_src2),
		.has_src1(has_src1)
  );

  wire [`WORD_WIDTH-1:0] ID_reg_pc_out;
  wire [`WORD_WIDTH-1:0] ID_reg_instruction_out;
  wire [`REG_FILE_DEPTH-1:0] ID_reg_reg_file_dst_out;
  wire [`WORD_WIDTH-1:0] ID_reg_val_Rn_out, ID_reg_val_Rm_out;
  wire [`SIGNED_IMM_WIDTH-1:0] ID_reg_signed_immediate_out;
  wire [`SHIFTER_OPERAND_WIDTH-1:0] ID_reg_shifter_operand_out;
  wire [3:0] ID_reg_SR_out, ID_reg_EX_command_out;
  wire ID_reg_mem_read_out, ID_reg_mem_write_out,
    ID_reg_WB_en_out,
    ID_reg_Imm_out,
    ID_reg_B_out,
    ID_reg_SR_update_out;
  wire [`REG_FILE_DEPTH-1:0] ID_reg_reg_file_src1, ID_reg_reg_file_src2;

  ID_Reg ID_Reg_Inst(
    .clk(clk),
    .rst(rst),
    .flush(EXE_stage_B_out),
    .pc_in(ID_stage_pc_out),
    .instruction_in(ID_stage_instruction_out),
    .reg_file_dst_in(ID_stage_reg_file_dst),
	  .val_Rn_in(ID_stage_val_Rn), .val_Rm_in(ID_stage_val_Rm),
	  .signed_immediate_in(ID_stage_signed_immediate),
	  .shifter_operand_in(ID_stage_shifter_operand),
    .EX_command_in(ID_stage_EX_command_out),
	  .mem_read_in(ID_stage_mem_read_out), .mem_write_in(ID_stage_mem_write_out),
		.WB_en_in(ID_stage_WB_en_out),
		.Imm_in(ID_stage_Imm_out),
		.B_in(ID_stage_B_out),
		.SR_update_in(ID_stage_SR_update_out),
    .reg_file_src1_in(ID_stage_reg_file_src1),
    .reg_file_src2_in(ID_stage_reg_file_src2),
    .pc(ID_reg_pc_out),
    .instruction(ID_reg_instruction_out),
    .reg_file_dst_out(ID_reg_reg_file_dst_out),
	  .val_Rn_out(ID_reg_val_Rn_out), .val_Rm_out(ID_reg_val_Rm_out),
	  .signed_immediate_out(ID_reg_signed_immediate_out),
	  .shifter_operand_out(ID_reg_shifter_operand_out),
    .EX_command_out(ID_reg_EX_command_out),
	  .mem_read_out(ID_reg_mem_read_out), .mem_write_out(ID_reg_mem_write_out),
		.WB_en_out(ID_reg_WB_en_out),
		.Imm_out(ID_reg_Imm_out),
		.B_out(ID_reg_B_out),
    .SR_update_out(ID_reg_SR_update_out),
    .status_register_in(status),
    .status_register_out(ID_reg_SR_out),
    .reg_file_src1_out(ID_reg_reg_file_src1),
    .reg_file_src2_out(ID_reg_reg_file_src2)
  );

  wire [`WORD_WIDTH-1:0] EXE_stage_pc_out;
  wire [`WORD_WIDTH-1:0] EXE_stage_instruction_out;
  wire [`REG_FILE_DEPTH-1:0] EXE_stage_reg_file_dst_out;
  wire [`WORD_WIDTH-1:0] EXE_stage_val_Rm_out;
  wire [3:0] EXE_stage_SR_out;
  wire [`WORD_WIDTH-1:0] ALU_res;
  wire EXE_stage_mem_read_out, EXE_stage_mem_write_out,
    EXE_stage_WB_en_out;

  wire [1:0] EXE_sel_src1, EXE_sel_src2;
  wire [`WORD_WIDTH-1:0] Mem_Stage_ALU_res_out;

  EXE_Stage EXE_Stage_Inst(
    .clk(clk),
    .rst(rst),
    .pc_in(ID_reg_pc_out),
    .instruction_in(ID_reg_instruction_out),
    .MEM_stage_val(Mem_Stage_ALU_res_out),
    .WB_stage_val(WB_Value),
    .signed_immediate(ID_reg_signed_immediate_out),
    .EX_command(ID_reg_EX_command_out),
    .SR_in(ID_reg_SR_out),
    .shifter_operand(ID_reg_shifter_operand_out),
    .dst_in(ID_reg_reg_file_dst_out),
    .mem_read_in(ID_reg_mem_read_out), .mem_write_in(ID_reg_mem_write_out),
    .imm(ID_reg_Imm_out),
    .WB_en_in(ID_reg_WB_en_out),
    .B_in(ID_reg_B_out),
    .val_Rn_in(ID_reg_val_Rn_out), .val_Rm_in(ID_reg_val_Rm_out),

    .sel_src1(EXE_sel_src1),
    .sel_src2(EXE_sel_src2),

    .dst_out(EXE_stage_reg_file_dst_out),
    .SR_out(EXE_stage_SR_out),
    .ALU_res(ALU_res),
    .val_Rm_out(EXE_stage_val_Rm_out),
    .branch_address(branch_address),
    .mem_read_out(EXE_stage_mem_read_out), .mem_write_out(EXE_stage_mem_write_out),
    .WB_en_out(EXE_stage_WB_en_out),
    .B_out(EXE_stage_B_out),
    .pc(EXE_stage_pc_out),
    .instruction(EXE_stage_instruction_out)
  );

  wire [`WORD_WIDTH-1:0] EXE_reg_pc_out;
  wire [`WORD_WIDTH-1:0] EXE_reg_instruction_out;
  wire [`REG_FILE_DEPTH-1:0] EXE_reg_dst_out;
  wire [`WORD_WIDTH-1:0] EXE_reg_ALU_res_out;
  wire [`WORD_WIDTH-1:0] EXE_reg_val_Rm_out;
  wire EXE_reg_mem_read_out, EXE_reg_mem_write_out, EXE_reg_WB_en_out;

  EXE_Reg EXE_Reg_Inst(
    .clk(clk),
    .rst(rst),
    .pc_in(EXE_stage_pc_out),
    .instruction_in(EXE_stage_instruction_out),
    .dst_in(EXE_stage_reg_file_dst_out),
    .mem_read_in(EXE_stage_mem_read_out), .mem_write_in(EXE_stage_mem_write_out),
    .WB_en_in(EXE_stage_WB_en_out),
    .val_Rm_in(EXE_stage_val_Rm_out),
    .ALU_res_in(ALU_res),
    .dst_out(EXE_reg_dst_out),
    .ALU_res_out(EXE_reg_ALU_res_out),
    .val_Rm_out(EXE_reg_val_Rm_out),
    .mem_read_out(EXE_reg_mem_read_out), .mem_write_out(EXE_reg_mem_write_out),
    .WB_en_out(EXE_reg_WB_en_out),
    .pc(EXE_reg_pc_out),
    .instruction(EXE_reg_instruction_out)
  );

  wire [`REG_FILE_DEPTH-1:0] Mem_Stage_dst_out;
  wire [`WORD_WIDTH-1:0] Mem_Stage_mem_out;
  wire Mem_Stage_read_out, Mem_Stage_WB_en_out;

  Mem_Stage Mem_Stage_Inst(
    .clk(clk),
    .rst(rst),
    .dst(EXE_reg_dst_out),
    .ALU_res(EXE_reg_ALU_res_out),
    .val_Rm(EXE_reg_val_Rm_out),
    .mem_read(EXE_reg_mem_read_out),
    .mem_write(EXE_reg_mem_write_out),
    .WB_en(EXE_reg_WB_en_out),
    .dst_out(Mem_Stage_dst_out),
    .ALU_res_out(Mem_Stage_ALU_res_out),
    .mem_out(Mem_Stage_mem_out),
    .mem_read_out(Mem_Stage_read_out),
    .WB_en_out(Mem_Stage_WB_en_out)
  );

  wire [`REG_FILE_DEPTH-1:0] Mem_Reg_dst_out;
  wire [`WORD_WIDTH-1:0] Mem_Reg_ALU_res_out;
  wire [`WORD_WIDTH-1:0] Mem_Reg_mem_out;
  wire Mem_Reg_read_out, Mem_Reg_WB_en_out;

  MEM_Reg Mem_Reg_Inst(
    .clk(clk),
    .rst(rst),
    .dst(Mem_Stage_dst_out),
    .ALU_res(Mem_Stage_ALU_res_out),
    .mem(Mem_Stage_mem_out),
    .mem_read(Mem_Stage_read_out),
    .WB_en(Mem_Stage_WB_en_out),

    .dst_out(Mem_Reg_dst_out),
    .ALU_res_out(Mem_Reg_ALU_res_out),
    .mem_out(Mem_Reg_mem_out),
    .mem_read_out(Mem_Reg_read_out),
    .WB_en_out(Mem_Reg_WB_en_out)
  );

  WB_Stage WB_Stage_Inst(
    .clk(clk),
    .rst(rst),
    .dst(Mem_Reg_dst_out),
    .ALU_res(Mem_Reg_ALU_res_out),
    .mem(Mem_Reg_mem_out),
    .mem_read(Mem_Reg_read_out),
    .WB_en(Mem_Reg_WB_en_out),
    .WB_Dest(WB_Stage_dst_out),
    .WB_en_out(WB_Stage_WB_en_out),
    .WB_Value(WB_Value)
  );

  Status_Reg Status_Reg_Inst(
    .clk(clk),
    .rst(rst),
    .load(ID_reg_SR_update_out),
    .status_in(EXE_stage_SR_out),
    .status(status)
  );

  wire EXE_WB_en = ID_reg_WB_en_out;
  wire MEM_WB_en = EXE_reg_WB_en_out;
  wire[`REG_FILE_DEPTH-1:0] EXE_dest = ID_reg_reg_file_dst_out;
  wire[`REG_FILE_DEPTH-1:0] MEM_dest = EXE_reg_dst_out;

  Hazard_Detection_Unit Hazard_Detection_Unit_Inst(
    .enableForwarding(enableForwarding),
    .src1(ID_stage_reg_file_src1),
    .src2(ID_stage_reg_file_src2),
    .EXE_dest(EXE_dest),
    .MEM_dest(MEM_dest),
    .EXE_WB_en(EXE_WB_en),
    .MEM_WB_en(MEM_WB_en),
    .EXE_memread_en(EXE_stage_mem_read_out),
    .has_src1(has_src1),
    .has_src2(has_src2),
    .hazard_detected(hazard_detected)
  );

  Forwarding_Unit Forwarding_Unit_Inst(
    .enable(enableForwarding),
    .src1(ID_reg_reg_file_src1),
    .src2(ID_reg_reg_file_src2),
    .MEM_dest(MEM_dest),
    .WB_dest(WB_Stage_dst_out),
    .MEM_WB_en(MEM_WB_en),
    .WB_WB_en(WB_Stage_WB_en_out),
    .sel_src1(EXE_sel_src1),
    .sel_src2(EXE_sel_src2)
  );

endmodule