Subversion Repositories an-fpga-implementation-of-low-latency-noc-based-mpsoc

/******************************************************************************

 This Source Code Form is subject to the terms of the

 Open Hardware Description License, v. 1.0. If a copy

 of the OHDL was not distributed with this file, You

 can obtain one at http://juliusbaxter.net/ohdl/ohdl.txt

 Description:

 Simple single clocked dual port ram (separate read and write ports),

 with optional bypass logic.

 Copyright (C) 2012 Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>

 ******************************************************************************/

`timescale       1ns/1ps

module mor1kx_simple_dpram_sclk

  #(

    parameter ADDR_WIDTH = 32,

    parameter DATA_WIDTH = 32,

    parameter ENABLE_BYPASS = 1

    )

   (

    input                   clk,

    input [ADDR_WIDTH-1:0]  raddr,

    input                   re,

    input [ADDR_WIDTH-1:0]  waddr,

    input                   we,

    input [DATA_WIDTH-1:0]  din,

    output [DATA_WIDTH-1:0] dout

    );

   reg [DATA_WIDTH-1:0]     mem[(1<<ADDR_WIDTH)-1:0];

   reg [DATA_WIDTH-1:0]     rdata;

generate

if (ENABLE_BYPASS) begin : bypass_gen

   reg [DATA_WIDTH-1:0]     din_r;

   reg                      bypass;

   assign dout = bypass ? din_r : rdata;

   always @(posedge clk)

     if (re)

       din_r <= din;

   always @(posedge clk)

     if (waddr == raddr && we && re)

       bypass <= 1;

     else if (re)

       bypass <= 0;

end else begin

   assign dout = rdata;

end

endgenerate

   always @(posedge clk) begin

      if (we)

        mem[waddr] <= din;

      if (re)

        rdata <= mem[raddr];

   end

endmodule