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//////////////////////////////////////////////////////////////////
// //
// Generic Library SRAM with per byte write enable //
// //
// This file is part of the Amber project //
// http://www.opencores.org/project,amber //
// //
// Description //
// Configurable depth and width. The DATA_WIDTH must be a //
// multiple of 8. //
// //
// Author(s): //
// - Conor Santifort, csantifort.amber@gmail.com //
// //
//////////////////////////////////////////////////////////////////
// //
// Copyright (C) 2010 Authors and OPENCORES.ORG //
// //
// 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 //
// //
//////////////////////////////////////////////////////////////////
// expect-wr-ports 1
// expect-rd-ports 1
module generic_sram_byte_en
#(
parameter DATA_WIDTH = 32,
parameter ADDRESS_WIDTH = 4
)
(
input i_clk,
input [DATA_WIDTH-1:0] i_write_data,
input i_write_enable,
input [ADDRESS_WIDTH-1:0] i_address,
input [DATA_WIDTH/8-1:0] i_byte_enable,
output reg [DATA_WIDTH-1:0] o_read_data
);
reg [DATA_WIDTH-1:0] mem [0:2**ADDRESS_WIDTH-1];
integer i;
always @(posedge i_clk)
begin
// read
o_read_data <= i_write_enable ? {DATA_WIDTH{1'd0}} : mem[i_address];
// write
if (i_write_enable)
for (i=0;i<DATA_WIDTH/8;i=i+1)
begin
mem[i_address][i*8+0] <= i_byte_enable[i] ? i_write_data[i*8+0] : mem[i_address][i*8+0] ;
mem[i_address][i*8+1] <= i_byte_enable[i] ? i_write_data[i*8+1] : mem[i_address][i*8+1] ;
mem[i_address][i*8+2] <= i_byte_enable[i] ? i_write_data[i*8+2] : mem[i_address][i*8+2] ;
mem[i_address][i*8+3] <= i_byte_enable[i] ? i_write_data[i*8+3] : mem[i_address][i*8+3] ;
mem[i_address][i*8+4] <= i_byte_enable[i] ? i_write_data[i*8+4] : mem[i_address][i*8+4] ;
mem[i_address][i*8+5] <= i_byte_enable[i] ? i_write_data[i*8+5] : mem[i_address][i*8+5] ;
mem[i_address][i*8+6] <= i_byte_enable[i] ? i_write_data[i*8+6] : mem[i_address][i*8+6] ;
mem[i_address][i*8+7] <= i_byte_enable[i] ? i_write_data[i*8+7] : mem[i_address][i*8+7] ;
end
end
endmodule
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