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

////                                                              ////

////  Generic Single-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 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              ////

////                                                              ////

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

////                                                              ////

//// 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

  (

`ifdef OR1200_BIST

   // RAM BIST

   mbist_si_i, mbist_so_o, mbist_ctrl_i,

`endif

   // Generic synchronous single-port RAM interface

   clk, ce, we, addr, di, doq

`ifdef OR1200_RAM_PARITY

   , p_err

`endif

   );

   //

   // Default address and data buses width

   //

   parameter aw = 10;

   parameter dw = 32;

`ifdef OR1200_BIST

   //

   // RAM BIST

   //

   input mbist_si_i;

   input [`OR1200_MBIST_CTRL_WIDTH - 1:0] mbist_ctrl_i;

   output                                 mbist_so_o;

`endif

   //

   // Generic synchronous single-port RAM interface

   //

   input                                  clk;  // Clock

   input                                  ce;   // Chip enable input

   input                                  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

`ifdef OR1200_RAM_PARITY

   output                                 p_err; // parity error indicator

`endif

   //

   // Internal wires and registers

   //

   //

   // Generic single-port synchronous RAM model

   //

   //

   // Generic RAM's registers and wires

   //

`ifdef OR1200_RAM_PARITY

   reg [(dw+(dw/8))-1:0]                   mem [(1<<aw)-1:0] /*synthesis syn_ramstyle = "no_rw_check"*/;

`else

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

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

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

`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];

   // Indicate error

   assign p_err = (|parity_err);

   // 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]             gpr_no;

      input [31:0]               parity_bit_no;

      input [31:0]               data_bit_no;

      reg [(dw+(dw/8))-1:0]      do_temp;

      begin

         do_temp = mem[gpr_no];

         // Switch parity bit

         if (parity_bit_no > 0 && parity_bit_no <= (dw/8))

           do_temp[dw+(parity_bit_no-1)] = ~do_temp[dw+(parity_bit_no-1)];

         // Switch data bit

         if (data_bit_no > 0 && data_bit_no <= dw)

           do_temp[data_bit_no-1] = ~do_temp[data_bit_no-1];

         // Write word back

         mem[gpr_no] = do_temp;

      end

   endtask // gen_parity_err

`endif

   //

   // Data output drivers

   //

   assign doq_wire = mem[addr_reg];

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

   //

   // RAM read address register

   //

   always @(posedge clk)

     if (ce)

       addr_reg <=  addr;

   //

   // RAM write

   //

   always @(posedge clk)

     if (we && ce)

`ifdef OR1200_RAM_PARITY

       mem[addr] <=  {di_p,di};

`else

       mem[addr] <=  di;

`endif

endmodule // or1200_spram