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

////                                                              ////

////  Generic Single-Port Synchronous RAM 32-bit Byte-Write       ////

////                                                              ////

////  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 single-port             ////

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

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

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

////  single-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.                               ////

////                                                              ////

////  Author(s):                                                  ////

////      - Michael Unneback, unneback@opencores.org              ////

////      - Tadej Markovic, tadej.markovic@gmail.com              ////

////                                                              ////

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

////                                                              ////

//// 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: or1200_dpram_32x32.v,v $

// Revision 2.0  2010/06/30 11:00:00  ORSoC

// New 

//

// synopsys translate_off

`include "timescale.v"

// synopsys translate_on

`include "or1200_defines.v"

module or1200_spram_32_bw

  (

`ifdef OR1200_BIST

   // RAM BIST

   mbist_si_i, mbist_so_o, mbist_ctrl_i,

`endif

   // Generic synchronous single-port RAM interface

   clk, rst, ce, we, addr, di, doq

`ifdef OR1200_RAM_PARITY

   , p_err

`endif

   );

   //

   // Default address and data buses width

   //

   parameter aw = 10;

   parameter dw = 32;

   parameter bw = 8;

`ifdef OR1200_BIST

   //

   // RAM BIST

   //

   input mbist_si_i;

   input [`OR1200_MBIST_CTRL_WIDTH - 1:0] mbist_ctrl_i;

   output                                 mbist_so_o;

`endif

`ifdef OR1200_RAM_PARITY

   output                                 p_err; // parity error indicator

`endif

   //

   // Generic synchronous single-port byte-writable RAM interface

   //

   input                                  clk;  // Clock

   input                                  rst;  // Reset

   input                                  ce;   // Chip enable input

   input [3:0]                             we;   // Write enable input

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

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

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

   //

   // Internal wires and registers

   //

   //

   // Generic single-port synchronous RAM model

   //

   //

   // Generic RAM's registers and wires

   //

`ifdef OR1200_RAM_PARITY

   reg [bw:0]    mem0 [(1<<aw)-1:0] /*synthesis syn_ramstyle = "no_rw_check"*/;

   reg [bw:0]    mem1 [(1<<aw)-1:0] /*synthesis syn_ramstyle = "no_rw_check"*/;

   reg [bw:0]    mem2 [(1<<aw)-1:0] /*synthesis syn_ramstyle = "no_rw_check"*/;

   reg [bw:0]    mem3 [(1<<aw)-1:0] /*synthesis syn_ramstyle = "no_rw_check"*/;

`else

   reg [bw-1:0] mem0 [(1<<aw)-1:0] /*synthesis syn_ramstyle = "no_rw_check"*/;

   reg [bw-1:0] mem1 [(1<<aw)-1:0] /*synthesis syn_ramstyle = "no_rw_check"*/;

   reg [bw-1:0] mem2 [(1<<aw)-1:0] /*synthesis syn_ramstyle = "no_rw_check"*/;

   reg [bw-1:0] mem3 [(1<<aw)-1:0] /*synthesis syn_ramstyle = "no_rw_check"*/;

`endif

   reg [aw-1:0] addr_reg;                // RAM address register

`ifdef OR1200_RAM_PARITY

   wire [(dw+(dw/8))-1:0]                  doq_wire;

   wire [bw:0]                             doq0_wire;

   wire [bw:0]                             doq1_wire;

   wire [bw:0]                             doq2_wire;

   wire [bw:0]                             doq3_wire;

   wire [(dw/8)-1:0]                       di_p;

   wire [(dw/8)-1:0]                       do_p;

   wire [(dw/8)-1:0]                       parity_err;

   reg                                    ce_r;

`else

   wire [dw-1:0]                           doq_wire;

`endif

`ifdef OR1200_RAM_PARITY

   genvar                       i;

   generate

      for (i=0;i<(dw/8);i=i+1) begin: paritygen

         or1200_parity_gen pgen(.d_i(di[(i*8)+7:(i*8)]), .p_o(di_p[i]));

         or1200_parity_chk pchk(.d_i(doq_wire[(i*8)+7:(i*8)]),

                                .p_i(do_p[i]), .err_o(parity_err[i]));

      end

   endgenerate

   // Extract parity bits of data out

   assign do_p = doq_wire[(dw+(dw/8))-1:dw];

   always @(posedge clk)

     if (rst)

       ce_r <= 0;

     else

       ce_r <= ce;

   // Indicate error

   assign p_err = (|parity_err) & ce_r;

   // Inject a parity error. Can specify GPR number to affect,

   // and which parity or data bit to switch.

   task gen_parity_err;

      input [aw-1:0]             word_no;

      input [31:0]               data_bit_no;

      reg [bw:0]                 do_temp;

      begin

         // Fish word out

         if (data_bit_no < 8) begin

            do_temp = mem0[word_no];

         end

         else if (data_bit_no < 16) begin

            do_temp = mem1[word_no];

            data_bit_no = data_bit_no - 8;

         end

         else if (data_bit_no < 24) begin

            do_temp = mem2[word_no];

            data_bit_no = data_bit_no - 16;

         end

         else if (data_bit_no < 32) begin

            do_temp = mem3[word_no];

            data_bit_no = data_bit_no - 24;

         end

         else begin

            do_temp = mem3[word_no];

            data_bit_no = 8;

         end

         // Switch bit

         do_temp[data_bit_no] = ~do_temp[data_bit_no] ;

         // Replace word

         if (data_bit_no < 8)

            mem0[word_no] = do_temp;

         else if (data_bit_no < 16)

            mem1[word_no] = do_temp;

         else if (data_bit_no < 24)

           mem2[word_no] = do_temp;

         else

            mem3[word_no] = do_temp;

      end

   endtask // gen_parity_err

`endif

   //

   // Data output drivers

   //

`ifdef OR1200_RAM_PARITY

   assign doq0_wire = mem0[addr_reg];

   assign doq1_wire = mem1[addr_reg];

   assign doq2_wire = mem2[addr_reg];

   assign doq3_wire = mem3[addr_reg];

   assign doq_wire = {// Parity bits

                      doq0_wire[bw],doq1_wire[bw],doq2_wire[bw],doq3_wire[bw],

                      // Data bytes

                      doq0_wire[bw-1:0],doq1_wire[bw-1:0],

                      doq2_wire[bw-1:0],doq3_wire[bw-1:0]};

`else

   assign doq_wire = {mem0[addr_reg], mem1[addr_reg], mem2[addr_reg], mem3[addr_reg]};

`endif

   assign doq = doq_wire[dw-1:0];

   //

   // RAM read address register

   //

   always @(posedge clk)

     if (ce)

       addr_reg <=  addr;

   //

   // RAM write - big endian selection

   //

   always @(posedge clk)

     if (ce) begin

`ifdef OR1200_RAM_PARITY

        if (we[3])

          mem0[addr] <=  {di_p[3],di[(bw*3)+(bw-1):(bw*3)]};

        if (we[2])

          mem1[addr] <=  {di_p[2],di[(bw*2)+(bw-1):(bw*2)]};

        if (we[1])

          mem2[addr] <=  {di_p[1],di[(bw*1)+(bw-1):(bw*1)]};

        if (we[0])

          mem3[addr] <=  {di_p[0],di[(bw*0)+(bw-1):(bw*0)]};

`else

        if (we[3])

          mem0[addr] <=  di[(bw*3)+(bw-1):(bw*3)];

        if (we[2])

          mem1[addr] <=  di[(bw*2)+(bw-1):(bw*2)];

        if (we[1])

          mem2[addr] <=  di[(bw*1)+(bw-1):(bw*1)];

        if (we[0])

          mem3[addr] <=  di[(bw*0)+(bw-1):(bw*0)];

`endif

     end

endmodule // or1200_spram_32_bw