Subversion Repositories s1_core

// ========== Copyright Header Begin ==========================================

// 

// OpenSPARC T1 Processor File: sparc_ifu_ctr5.v

// Copyright (c) 2006 Sun Microsystems, Inc.  All Rights Reserved.

// DO NOT ALTER OR REMOVE COPYRIGHT NOTICES.

// 

// The above named program is free software; you can redistribute it and/or

// modify it under the terms of the GNU General Public

// License version 2 as published by the Free Software Foundation.

// 

// The above named program 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

// General Public License for more details.

// 

// You should have received a copy of the GNU General Public

// License along with this work; if not, write to the Free Software

// Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.

// 

// ========== Copyright Header End ============================================

`ifdef SIMPLY_RISC_TWEAKS

`define SIMPLY_RISC_SCANIN .si(0)

`else

`define SIMPLY_RISC_SCANIN .si()

`endif

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

/*

//  Module Name: sparc_ifu_ctr5

//  Description:

//  5 bit counter for starvation detect

*/

module sparc_ifu_ctr5(/*AUTOARG*/

   // Outputs

   limit, so,

   // Inputs

   clk, se, si, rst_ctr_l

   );

   input     clk;

   input     se, si;

   input     rst_ctr_l;

   output    limit;

   output    so;

   wire [4:0] count,

              count_nxt,

              sum;

   assign   sum[0] = ~count[0];

   assign   sum[1] = count[1] ^ count[0];

   assign   sum[2] = count[2] ^ (count[1] & count[0]);

   assign   sum[3] = count[3] ^ (count[2] & count[1] & count[0]);

   assign   sum[4] = count[4] ^ (count[3] & count[2] & count[1] & count[0]);

   assign   count_nxt = sum & {5{rst_ctr_l}};

   dff_s #(5) cnt_reg(.din (count_nxt),

                                .q   (count),

                                .clk (clk),

                                .se  (se), `SIMPLY_RISC_SCANIN, .so());

   // limit set to 24 for now

   assign   limit = count[4] & count[3];

endmodule