///////////////////////////////////////////
// muldiv.sv
//
// Written: David_Harris@hmc.edu 9 January 2021
// Modified: 
//
// Purpose: M extension multiply and divide
// 
// A component of the Wally configurable RISC-V project.
// 
// Copyright (C) 2021 Harvey Mudd College & Oklahoma State University
//
// Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation
// files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, 
// modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software 
// is furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES 
// OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS 
// BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT 
// OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
///////////////////////////////////////////

`include "wally-config.vh"

module muldiv (
  input  logic             clk, reset,
  // Decode Stage interface
  input  logic [31:0]      InstrD, 
  // Execute Stage interface
  input  logic [`XLEN-1:0] SrcAE, SrcBE,
  input  logic             MulDivE, W64E,
  // Writeback stage
  output logic [`XLEN-1:0] MulDivResultW,
  // hazards
  input  logic             FlushM, FlushW // ***fewer?
);
           
  logic [`XLEN*2-1:0] ProdE;
  logic [`XLEN-1:0] MulDivResultE, MulDivResultM;

  assign ProdE = SrcAE * SrcBE;
  assign MulDivResultE = ProdE[`XLEN-1:0];

  floprc #(`XLEN) MulDivResultMReg(clk, reset, FlushM, MulDivResultE, MulDivResultM);
  floprc #(`XLEN) MulDivResultWReg(clk, reset, FlushW, MulDivResultM, MulDivResultW);

endmodule