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//////////////////////////////////////////////////////////////////////

////                                                              ////

////  Generic Two-Port Synchronous RAM                            ////

////                                                              ////

////  This file is part of memory library available from          ////

////  http://www.opencores.org/cvsweb.shtml/generic_memories/     ////

////                                                              ////

////  Description                                                 ////

////  This block is a wrapper with common two-port                ////

////  synchronous memory interface for different                  ////

////  types of ASIC and FPGA RAMs. Beside universal memory        ////

////  interface it also provides behavioral model of generic      ////

////  two-port synchronous RAM.                                   ////

////  It should be used in all OPENCORES designs that want to be  ////

////  portable accross different target technologies and          ////

////  independent of target memory.                               ////

////                                                              ////

////  Supported ASIC RAMs are:                                    ////

////  - Artisan Double-Port Sync RAM                              ////

////  - Avant! Two-Port Sync RAM (*)                              ////

////  - Virage 2-port Sync RAM                                    ////

////                                                              ////

////  Supported FPGA RAMs are:                                    ////

////  - Xilinx Virtex RAMB4_S16_S16                               ////

////                                                              ////

////  To Do:                                                      ////

////   - fix Avant!                                               ////

////   - xilinx rams need external tri-state logic                ////

////   - add additional RAMs (Altera, VS etc)                     ////

////                                                              ////

////  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 1.1  2001/11/07 18:10:21  samg

// added checks and task in behavioral section

//

// Revision 1.7  2001/10/21 17:57:16  lampret

// Removed params from generic_XX.v. Added translate_off/on in sprs.v and id.v. Removed spr_addr from dc.v and ic.v. Fixed CR+LF.

//

// Revision 1.6  2001/10/14 13:12:09  lampret

// MP3 version.

//

// Revision 1.1.1.1  2001/10/06 10:18:36  igorm

// no message

//

// Revision 1.1  2001/08/09 13:39:33  lampret

// Major clean-up.

//

// Revision 1.2  2001/07/30 05:38:02  lampret

// Adding empty directories required by HDL coding guidelines

//

//

// synopsys translate_off

//`include "timescale.v"

// synopsys translate_on

//`include "defines.v"

module generic_tpram(

        // Generic synchronous two-port RAM interface

        clk_a, rst_a, ce_a, we_a, oe_a, addr_a, di_a, do_a,

        clk_b, rst_b, ce_b, we_b, oe_b, addr_b, di_b, do_b

);

//

// Default address and data buses width

//

parameter aw = 5;

parameter dw = 32;

parameter MEM_SIZE = (1<<aw);

//

// Generic synchronous two-port RAM interface

//

input                   clk_a;  // Clock

input                   rst_a;  // Reset

input                   ce_a;   // Chip enable input

input                   we_a;   // Write enable input

input                   oe_a;   // Output enable input

input   [aw-1:0] addr_a; // address bus inputs

input   [dw-1:0] di_a;   // input data bus

output  [dw-1:0] do_a;   // output data bus

input                   clk_b;  // Clock

input                   rst_b;  // Reset

input                   ce_b;   // Chip enable input

input                   we_b;   // Write enable input

input                   oe_b;   // Output enable input

input   [aw-1:0] addr_b; // address bus inputs

input   [dw-1:0] di_b;   // input data bus

output  [dw-1:0] do_b;   // output data bus

//

// Internal wires and registers

//

`ifdef ARTISAN_SDP

//

// Instantiation of ASIC memory:

//

// Artisan Synchronous Double-Port RAM (ra2sh)

//

`ifdef UNUSED

art_hsdp_32x32 #(dw, 1<<aw, aw) artisan_sdp(

`else

art_hsdp_32x32 artisan_sdp(

`endif

        .qa(do_a),

        .clka(clk_a),

        .cena(~ce_a),

        .wena(~we_a),

        .aa(addr_a),

        .da(di_a),

        .oena(~oe_a),

        .qb(do_b),

        .clkb(clk_b),

        .cenb(~ce_b),

        .wenb(~we_b),

        .ab(addr_b),

        .db(di_b),

        .oenb(~oe_b)

);

`else

`ifdef AVANT_ATP

//

// Instantiation of ASIC memory:

//

// Avant! Asynchronous Two-Port RAM

//

avant_atp avant_atp(

        .web(~we),

        .reb(),

        .oeb(~oe),

        .rcsb(),

        .wcsb(),

        .ra(addr),

        .wa(addr),

        .di(di),

        .do(do)

);

`else

`ifdef VIRAGE_STP

//

// Instantiation of ASIC memory:

//

// Virage Synchronous 2-port R/W RAM

//

virage_stp virage_stp(

        .QA(do_a),

        .QB(do_b),

        .ADRA(addr_a),

        .DA(di_a),

        .WEA(we_a),

        .OEA(oe_a),

        .MEA(ce_a),

        .CLKA(clk_a),

        .ADRB(adr_b),

        .DB(di_b),

        .WEB(we_b),

        .OEB(oe_b),

        .MEB(ce_b),

        .CLKB(clk_b)

);

`else

`ifdef XILINX_RAMB4

//

// Instantiation of FPGA memory:

//

// Virtex/Spartan2

//

//

// Block 0

//

RAMB4_S16_S16 ramb4_s16_s16_0(

        .CLKA(clk_a),

        .RSTA(rst_a),

        .ADDRA(addr_a),

        .DIA(di_a[15:0]),

        .ENA(ce_a),

        .WEA(we_a),

        .DOA(do_a[15:0]),

        .CLKB(clk_b),

        .RSTB(rst_b),

        .ADDRB(addr_b),

        .DIB(di_b[15:0]),

        .ENB(ce_b),

        .WEB(we_b),

        .DOB(do_b[15:0])

);

//

// Block 1

//

RAMB4_S16_S16 ramb4_s16_s16_1(

        .CLKA(clk_a),

        .RSTA(rst_a),

        .ADDRA(addr_a),

        .DIA(di_a[31:16]),

        .ENA(ce_a),

        .WEA(we_a),

        .DOA(do_a[31:16]),

        .CLKB(clk_b),

        .RSTB(rst_b),

        .ADDRB(addr_b),

        .DIB(di_b[31:16]),

        .ENB(ce_b),

        .WEB(we_b),

        .DOB(do_b[31:16])

);

`else

//

// Generic two-port synchronous RAM model

//

//

// Generic RAM's registers and wires

//

reg     [dw-1:0] mem [(1<<aw)-1:0];       // RAM content

wire    [dw-1:0] do_reg_a;               // RAM data output register

wire    [dw-1:0] do_reg_b;               // RAM data output register

reg     [dw-1:0] do_wc_reg_a;            // RAM data output register (write check)

reg     [dw-1:0] do_wc_reg_b;            // RAM data output register (write check)

//

// Data output drivers

//

// Output only valid when output enabled and chip enbled

assign do_a = (oe_a & ce_a) ? do_reg_a : {dw{1'bz}};

assign do_b = (oe_b & ce_b) ? do_reg_b : {dw{1'bz}};

// Output is invalid while writing data 

assign do_reg_a = (we_a) ? {dw{1'b x}} : do_wc_reg_a;

assign do_reg_b = (we_b) ? {dw{1'b x}} : do_wc_reg_b;

//

// RAM read and write

//

always @(posedge clk_a)

        if (ce_a && !we_a)

                do_wc_reg_a <= #1 (we_b && (addr_a==addr_b)) ? {dw{1'b x}} : mem[addr_a];

        else if (ce_a && we_a)

                mem[addr_a] <= #1 di_a;

//

// RAM read and write

//

always @(posedge clk_b)

        if (ce_b && !we_b)

                do_wc_reg_b <= #1 (we_a && (addr_a==addr_b)) ? {dw{1'b x}} : mem[addr_b];

        else if (ce_b && we_b)

                mem[addr_b] <= #1 di_b;

// Task prints range of memory

// *** Remember that tasks are non reentrant, don't call this task in parallel for multiple instantiations. 

task print_ram;

input [aw-1:0] start;

input [aw-1:0] finish;

integer rnum;

  begin

    for (rnum=start;rnum<=finish;rnum=rnum+1)

      $display("Addr %h = %h",rnum,mem[rnum]);

  end

endtask

`endif  // !XILINX_RAMB4_S16_S16

`endif  // !VIRAGE_STP

`endif  // !AVANT_ATP

`endif  // !ARTISAN_SDP

endmodule