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//////////////////////////////////////////////////////////////////////
////                                                              ////
////  OR1200's reg2mem aligner                                    ////
////                                                              ////
////  This file is part of the OpenRISC 1200 project              ////
////  http://www.opencores.org/cores/or1k/                        ////
////                                                              ////
////  Description                                                 ////
////  Aligns register data to memory alignment.                   ////
////                                                              ////
////  To Do:                                                      ////
////   - make it smaller and faster                               ////
////                                                              ////
////  Author(s):                                                  ////
////      - Damjan Lampret, lampret@opencores.org                 ////
////                                                              ////
//////////////////////////////////////////////////////////////////////
////                                                              ////
//// Copyright (C) 2000 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                     ////
////                                                              ////
//////////////////////////////////////////////////////////////////////
//
// CVS Revision History
//
// $Log: not supported by cvs2svn $
// Revision 1.2  2001/08/09 13:39:33  lampret
// Major clean-up.
//
// Revision 1.1  2001/07/20 00:46:21  lampret
// Development version of RTL. Libraries are missing.
//
//
 
// synopsys translate_off
`include "timescale.v"
// synopsys translate_on
`include "defines.v"
 
module reg2mem(addr, lsu_op, regdata, memdata);
 
parameter width = `OPERAND_WIDTH;
 
//
// I/O
//
input	[1:0]			addr;
input	[`LSUOP_WIDTH-1:0]	lsu_op;
input	[width-1:0]		regdata;
output	[width-1:0]		memdata;
 
//
// Internal regs and wires
//
reg	[width-1:0]		memdata;
 
//
// Mux to memdata[31:24]
//
always @(lsu_op or addr or regdata) begin
	casex({lsu_op, addr[1:0]})	// synopsys full_case parallel_case
		{`LSUOP_SB, 2'b00} : memdata[31:24] = regdata[7:0];
		{`LSUOP_SH, 2'b00} : memdata[31:24] = regdata[15:8];
		default : memdata[31:24] = regdata[31:24];
	endcase
end
 
//
// Mux to memdata[23:16]
//
always @(lsu_op or addr or regdata) begin
	casex({lsu_op, addr[1:0]})	// synopsys full_case parallel_case
		{`LSUOP_SW, 2'b00} : memdata[23:16] = regdata[23:16];
		default : memdata[23:16] = regdata[7:0];
	endcase
end
 
//
// Mux to memdata[15:8]
//
always @(lsu_op or addr or regdata) begin
	casex({lsu_op, addr[1:0]})	// synopsys full_case parallel_case
		{`LSUOP_SB, 2'b10} : memdata[15:8] = regdata[7:0];
		default : memdata[15:8] = regdata[15:8];
	endcase
end
 
//
// Mux to memdata[7:0]
//
always @(regdata)
	memdata[7:0] = regdata[7:0];
 
endmodule