//////////////////////////////////////////////////////////////////////
////                                                              ////
//// Copyright (C) 2014 leishangwen@163.com                       ////
////                                                              ////
//// This source file may be used and distributed without         ////
//// restriction provided that this copyright statement is not    ////
//// removed from the file and that any derivative work contains  ////
//// the original copyright notice and the associated disclaimer. ////
////                                                              ////
//// This source file is free software; you can redistribute it   ////
//// and/or modify it under the terms of the GNU Lesser General   ////
//// Public License as published by the Free Software Foundation; ////
//// either version 2.1 of the License, or (at your option) any   ////
//// later version.                                               ////
////                                                              ////
//// This source is distributed in the hope that it will be       ////
//// useful, but WITHOUT ANY WARRANTY; without even the implied   ////
//// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR      ////
//// PURPOSE.  See the GNU Lesser General Public License for more ////
//// details.                                                     ////
////                                                              ////
//////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////
// Module:  openmips
// File:    openmips.v
// Author:  Lei Silei
// E-mail:  leishangwen@163.com
// Description: OpenMIPS处理器的顶层文件
// Revision: 1.0
//////////////////////////////////////////////////////////////////////

`include "defines.v"

module openmips(

	input	wire										clk,
	input wire										rst,
	
 
	input wire[`RegBus]           rom_data_i,
	output wire[`RegBus]           rom_addr_o,
	output wire                    rom_ce_o
	
);

	wire[`InstAddrBus] pc;
	wire[`InstAddrBus] id_pc_i;
	wire[`InstBus] id_inst_i;
	
	//连接译码阶段ID模块的输出与ID/EX模块的输入
	wire[`AluOpBus] id_aluop_o;
	wire[`AluSelBus] id_alusel_o;
	wire[`RegBus] id_reg1_o;
	wire[`RegBus] id_reg2_o;
	wire id_wreg_o;
	wire[`RegAddrBus] id_wd_o;
	wire id_is_in_delayslot_o;
  wire[`RegBus] id_link_address_o;	
	
	//连接ID/EX模块的输出与执行阶段EX模块的输入
	wire[`AluOpBus] ex_aluop_i;
	wire[`AluSelBus] ex_alusel_i;
	wire[`RegBus] ex_reg1_i;
	wire[`RegBus] ex_reg2_i;
	wire ex_wreg_i;
	wire[`RegAddrBus] ex_wd_i;
	wire ex_is_in_delayslot_i;	
  wire[`RegBus] ex_link_address_i;	
	
	//连接执行阶段EX模块的输出与EX/MEM模块的输入
	wire ex_wreg_o;
	wire[`RegAddrBus] ex_wd_o;
	wire[`RegBus] ex_wdata_o;
	wire[`RegBus] ex_hi_o;
	wire[`RegBus] ex_lo_o;
	wire ex_whilo_o;

	//连接EX/MEM模块的输出与访存阶段MEM模块的输入
	wire mem_wreg_i;
	wire[`RegAddrBus] mem_wd_i;
	wire[`RegBus] mem_wdata_i;
	wire[`RegBus] mem_hi_i;
	wire[`RegBus] mem_lo_i;
	wire mem_whilo_i;		

	//连接访存阶段MEM模块的输出与MEM/WB模块的输入
	wire mem_wreg_o;
	wire[`RegAddrBus] mem_wd_o;
	wire[`RegBus] mem_wdata_o;
	wire[`RegBus] mem_hi_o;
	wire[`RegBus] mem_lo_o;
	wire mem_whilo_o;		
	
	//连接MEM/WB模块的输出与回写阶段的输入	
	wire wb_wreg_i;
	wire[`RegAddrBus] wb_wd_i;
	wire[`RegBus] wb_wdata_i;
	wire[`RegBus] wb_hi_i;
	wire[`RegBus] wb_lo_i;
	wire wb_whilo_i;	
	
	//连接译码阶段ID模块与通用寄存器Regfile模块
  wire reg1_read;
  wire reg2_read;
  wire[`RegBus] reg1_data;
  wire[`RegBus] reg2_data;
  wire[`RegAddrBus] reg1_addr;
  wire[`RegAddrBus] reg2_addr;

	//连接执行阶段与hilo模块的输出，读取HI、LO寄存器
	wire[`RegBus] 	hi;
	wire[`RegBus]   lo;

  //连接执行阶段与ex_reg模块，用于多周期的MADD、MADDU、MSUB、MSUBU指令
	wire[`DoubleRegBus] hilo_temp_o;
	wire[1:0] cnt_o;
	
	wire[`DoubleRegBus] hilo_temp_i;
	wire[1:0] cnt_i;

	wire[`DoubleRegBus] div_result;
	wire div_ready;
	wire[`RegBus] div_opdata1;
	wire[`RegBus] div_opdata2;
	wire div_start;
	wire div_annul;
	wire signed_div;

	wire is_in_delayslot_i;
	wire is_in_delayslot_o;
	wire next_inst_in_delayslot_o;
	wire id_branch_flag_o;
	wire[`RegBus] branch_target_address;

	wire[5:0] stall;
	wire stallreq_from_id;	
	wire stallreq_from_ex;
  
  //pc_reg例化
	pc_reg pc_reg0(
		.clk(clk),
		.rst(rst),
		.stall(stall),
		.branch_flag_i(id_branch_flag_o),
		.branch_target_address_i(branch_target_address),		
		.pc(pc),
		.ce(rom_ce_o)		
			
	);
	
  assign rom_addr_o = pc;

  //IF/ID模块例化
	if_id if_id0(
		.clk(clk),
		.rst(rst),
		.stall(stall),
		.if_pc(pc),
		.if_inst(rom_data_i),
		.id_pc(id_pc_i),
		.id_inst(id_inst_i)      	
	);
	
	//译码阶段ID模块
	id id0(
		.rst(rst),
		.pc_i(id_pc_i),
		.inst_i(id_inst_i),

		.reg1_data_i(reg1_data),
		.reg2_data_i(reg2_data),

	  //处于执行阶段的指令要写入的目的寄存器信息
		.ex_wreg_i(ex_wreg_o),
		.ex_wdata_i(ex_wdata_o),
		.ex_wd_i(ex_wd_o),

	  //处于访存阶段的指令要写入的目的寄存器信息
		.mem_wreg_i(mem_wreg_o),
		.mem_wdata_i(mem_wdata_o),
		.mem_wd_i(mem_wd_o),

	  .is_in_delayslot_i(is_in_delayslot_i),

		//送到regfile的信息
		.reg1_read_o(reg1_read),
		.reg2_read_o(reg2_read), 	  

		.reg1_addr_o(reg1_addr),
		.reg2_addr_o(reg2_addr), 
	  
		//送到ID/EX模块的信息
		.aluop_o(id_aluop_o),
		.alusel_o(id_alusel_o),
		.reg1_o(id_reg1_o),
		.reg2_o(id_reg2_o),
		.wd_o(id_wd_o),
		.wreg_o(id_wreg_o),

	 	.next_inst_in_delayslot_o(next_inst_in_delayslot_o),	
		.branch_flag_o(id_branch_flag_o),
		.branch_target_address_o(branch_target_address),       
		.link_addr_o(id_link_address_o),
		
		.is_in_delayslot_o(id_is_in_delayslot_o),
		
		.stallreq(stallreq_from_id)		
	);

  //通用寄存器Regfile例化
	regfile regfile1(
		.clk (clk),
		.rst (rst),
		.we	(wb_wreg_i),
		.waddr (wb_wd_i),
		.wdata (wb_wdata_i),
		.re1 (reg1_read),
		.raddr1 (reg1_addr),
		.rdata1 (reg1_data),
		.re2 (reg2_read),
		.raddr2 (reg2_addr),
		.rdata2 (reg2_data)
	);

	//ID/EX模块
	id_ex id_ex0(
		.clk(clk),
		.rst(rst),
		
		.stall(stall),
		
		//从译码阶段ID模块传递的信息
		.id_aluop(id_aluop_o),
		.id_alusel(id_alusel_o),
		.id_reg1(id_reg1_o),
		.id_reg2(id_reg2_o),
		.id_wd(id_wd_o),
		.id_wreg(id_wreg_o),
		.id_link_address(id_link_address_o),
		.id_is_in_delayslot(id_is_in_delayslot_o),
		.next_inst_in_delayslot_i(next_inst_in_delayslot_o),		
	
		//传递到执行阶段EX模块的信息
		.ex_aluop(ex_aluop_i),
		.ex_alusel(ex_alusel_i),
		.ex_reg1(ex_reg1_i),
		.ex_reg2(ex_reg2_i),
		.ex_wd(ex_wd_i),
		.ex_wreg(ex_wreg_i),
		.ex_link_address(ex_link_address_i),
  	.ex_is_in_delayslot(ex_is_in_delayslot_i),
		.is_in_delayslot_o(is_in_delayslot_i)			
	);		
	
	//EX模块
	ex ex0(
		.rst(rst),
	
		//送到执行阶段EX模块的信息
		.aluop_i(ex_aluop_i),
		.alusel_i(ex_alusel_i),
		.reg1_i(ex_reg1_i),
		.reg2_i(ex_reg2_i),
		.wd_i(ex_wd_i),
		.wreg_i(ex_wreg_i),
		.hi_i(hi),
		.lo_i(lo),

	  .wb_hi_i(wb_hi_i),
	  .wb_lo_i(wb_lo_i),
	  .wb_whilo_i(wb_whilo_i),
	  .mem_hi_i(mem_hi_o),
	  .mem_lo_i(mem_lo_o),
	  .mem_whilo_i(mem_whilo_o),

	  .hilo_temp_i(hilo_temp_i),
	  .cnt_i(cnt_i),

		.div_result_i(div_result),
		.div_ready_i(div_ready), 

	  .link_address_i(ex_link_address_i),
		.is_in_delayslot_i(ex_is_in_delayslot_i),	  
			  
	  //EX模块的输出到EX/MEM模块信息
		.wd_o(ex_wd_o),
		.wreg_o(ex_wreg_o),
		.wdata_o(ex_wdata_o),

		.hi_o(ex_hi_o),
		.lo_o(ex_lo_o),
		.whilo_o(ex_whilo_o),

		.hilo_temp_o(hilo_temp_o),
		.cnt_o(cnt_o),

		.div_opdata1_o(div_opdata1),
		.div_opdata2_o(div_opdata2),
		.div_start_o(div_start),
		.signed_div_o(signed_div),	
		
		.stallreq(stallreq_from_ex)     				
		
	);

  //EX/MEM模块
  ex_mem ex_mem0(
		.clk(clk),
		.rst(rst),
	  
	  .stall(stall),
	  
		//来自执行阶段EX模块的信息	
		.ex_wd(ex_wd_o),
		.ex_wreg(ex_wreg_o),
		.ex_wdata(ex_wdata_o),
		.ex_hi(ex_hi_o),
		.ex_lo(ex_lo_o),
		.ex_whilo(ex_whilo_o),		

		.hilo_i(hilo_temp_o),
		.cnt_i(cnt_o),	

		//送到访存阶段MEM模块的信息
		.mem_wd(mem_wd_i),
		.mem_wreg(mem_wreg_i),
		.mem_wdata(mem_wdata_i),
		.mem_hi(mem_hi_i),
		.mem_lo(mem_lo_i),
		.mem_whilo(mem_whilo_i),
				
		.hilo_o(hilo_temp_i),
		.cnt_o(cnt_i)
						       	
	);
	
  //MEM模块例化
	mem mem0(
		.rst(rst),
	
		//来自EX/MEM模块的信息	
		.wd_i(mem_wd_i),
		.wreg_i(mem_wreg_i),
		.wdata_i(mem_wdata_i),
		.hi_i(mem_hi_i),
		.lo_i(mem_lo_i),
		.whilo_i(mem_whilo_i),		
	  
		//送到MEM/WB模块的信息
		.wd_o(mem_wd_o),
		.wreg_o(mem_wreg_o),
		.wdata_o(mem_wdata_o),
		.hi_o(mem_hi_o),
		.lo_o(mem_lo_o),
		.whilo_o(mem_whilo_o)		
	);

  //MEM/WB模块
	mem_wb mem_wb0(
		.clk(clk),
		.rst(rst),

    .stall(stall),

		//来自访存阶段MEM模块的信息	
		.mem_wd(mem_wd_o),
		.mem_wreg(mem_wreg_o),
		.mem_wdata(mem_wdata_o),
		.mem_hi(mem_hi_o),
		.mem_lo(mem_lo_o),
		.mem_whilo(mem_whilo_o),		
	
		//送到回写阶段的信息
		.wb_wd(wb_wd_i),
		.wb_wreg(wb_wreg_i),
		.wb_wdata(wb_wdata_i),
		.wb_hi(wb_hi_i),
		.wb_lo(wb_lo_i),
		.wb_whilo(wb_whilo_i)		
									       	
	);

	hilo_reg hilo_reg0(
		.clk(clk),
		.rst(rst),
	
		//写端口
		.we(wb_whilo_i),
		.hi_i(wb_hi_i),
		.lo_i(wb_lo_i),
	
		//读端口1
		.hi_o(hi),
		.lo_o(lo)	
	);
	
	ctrl ctrl0(
		.rst(rst),
	
		.stallreq_from_id(stallreq_from_id),
	
  	//来自执行阶段的暂停请求
		.stallreq_from_ex(stallreq_from_ex),

		.stall(stall)       	
	);

	div div0(
		.clk(clk),
		.rst(rst),
	
		.signed_div_i(signed_div),
		.opdata1_i(div_opdata1),
		.opdata2_i(div_opdata2),
		.start_i(div_start),
		.annul_i(1'b0),
	
		.result_o(div_result),
		.ready_o(div_ready)
	);

endmodule