Subversion Repositories xge_mac

//////////////////////////////////////////////////////////////////////
////                                                              ////
////  File name "generic_mem_small.v"                             ////
////                                                              ////
////  This file is part of the "10GE MAC" project                 ////
////  http://www.opencores.org/cores/xge_mac/                     ////
////                                                              ////
////  Author(s):                                                  ////
////      - A. Tanguay (antanguay@opencores.org)                  ////
////                                                              ////
//////////////////////////////////////////////////////////////////////
////                                                              ////
//// Copyright (C) 2008 AUTHORS. All rights reserved.             ////
////                                                              ////
//// 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.                                                     ////
////                                                              ////
//// You should have received a copy of the GNU Lesser General    ////
//// Public License along with this source; if not, download it   ////
//// from http://www.opencores.org/lgpl.shtml                     ////
////                                                              ////
//////////////////////////////////////////////////////////////////////
 
/* synthesis ramstyle = "M512" */
 
module generic_mem_small(
 
    wclk,
    wrst_n,
    wen,
    waddr,
    wdata,
 
    rclk,
    rrst_n,
    ren,
    roen,
    raddr,
    rdata
);
 
//---
// Parameters
 
parameter DWIDTH = 32;
parameter AWIDTH = 3;
parameter RAM_DEPTH = (1 << AWIDTH);
parameter REGISTER_READ = 0;
 
//---
// Ports
 
input               wclk;
input               wrst_n;
input               wen;
input  [AWIDTH-1:0] waddr;
input  [DWIDTH-1:0] wdata;
 
input               rclk;
input               rrst_n;
input               ren;
input               roen;
input  [AWIDTH-1:0] raddr;
output [DWIDTH-1:0] rdata;
 
// Registered outputs
reg    [DWIDTH-1:0] rdata;
 
 
//---
// Local declarations
 
// Registers
 
reg  [DWIDTH-1:0] mem_rdata;
 
 
// Memory
 
reg  [DWIDTH-1:0] mem [0:RAM_DEPTH-1];
 
// Variables
 
integer         i;
 
 
//---
// Memory Write
 
// Generate synchronous write
always @(posedge wclk)
begin
    if (wen) begin
        mem[waddr[AWIDTH-1:0]] <= wdata;
    end
end
 
//---
// Memory Read
 
// Generate registered memory read
always @(posedge rclk or negedge rrst_n)
begin
    if (!rrst_n) begin
        mem_rdata <= {(DWIDTH){1'b0}};
    end else if (ren) begin
        mem_rdata <= mem[raddr[AWIDTH-1:0]];
    end
end
 
generate
    if (REGISTER_READ) begin
 
        // Generate registered output
        always @(posedge rclk or negedge rrst_n)
        begin
            if (!rrst_n) begin
                rdata <= {(DWIDTH){1'b0}};
            end else if (roen) begin
                rdata <= mem_rdata;
            end
        end
 
    end
    else begin
 
        // Generate unregisters output
        always @(mem_rdata)
        begin
            rdata = mem_rdata;
        end
 
    end
endgenerate
 
endmodule