source: XOpenSparcT1/trunk/T1-common/common/cluster_header.v @ 6

// ========== Copyright Header Begin ==========================================
// 
// OpenSPARC T1 Processor File: cluster_header.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 ============================================
// The cluster header is instatiated as a hard macro.
// This model is for simulation only.
`include "sys.h"

module cluster_header (/*AUTOARG*/
   // Outputs
   dbginit_l, cluster_grst_l, rclk, so, 
   // Inputs
   gclk, cluster_cken, arst_l, grst_l, adbginit_l, gdbginit_l, si, 
   se
   );

   input       gclk;
   input       cluster_cken;
   input       arst_l;
   input       grst_l;
   input       adbginit_l;
   input       gdbginit_l; 
   output      dbginit_l; 
   output      cluster_grst_l;
   output      rclk;

   input       si; // scan ports for reset flop repeaters
   input       se;
   output      so;

`ifdef FPGA_SYN
//  assign #10 rclk = gclk;
//  assign #10 dbginit_l = gdbginit_l;
//  assign #10 cluster_grst_l = grst_l; 
//  assign so = 1'b0;

reg      dbginit_l; 
reg      cluster_grst_l;

assign #10 rclk = gclk;

always @(negedge rclk) begin
  dbginit_l <= gdbginit_l;
  cluster_grst_l <= grst_l;
end

`else
   
   wire        pre_sync_enable;
   wire        sync_enable;
   wire        cluster_grst_l;
   wire        dbginit_l;
   wire        rst_sync_so;

   bw_u1_syncff_4x sync_cluster_master ( // no scan hook-up
                                        .so(),
                                        .q (pre_sync_enable),
                                        .ck (gclk),
                                        .d (cluster_cken),
                                        .sd(1'b0),
                                        .se(1'b0)
                                        );
   

   bw_u1_scanl_2x sync_cluster_slave ( // use scan lock-up latch
                                      .so (sync_enable),
                                      .ck (gclk),
                                      .sd (pre_sync_enable)
                                      );
   
// NOTE! Pound delay in the below statement is meant to provide 10 ps
// delay between gclk and rclk to allow the synchronizer for rst, dbginit,
// and sync pulses to be modelled accurately.  gclk and rclk need to have 
// at least one simulator timestep separation to allow the flop->flop 
// synchronizer to work correctly.
   assign #10 rclk = gclk & sync_enable;

   synchronizer_asr rst_repeater (
                                 .sync_out(cluster_grst_l),
                                 .so(rst_sync_so),
                                 .async_in(grst_l),
                                 .gclk(gclk),
                                 .rclk(rclk),
                                 .arst_l(arst_l),
                                 .si(si),
                                 .se(se)
                                 );
   
   synchronizer_asr dbginit_repeater (
                                     .sync_out(dbginit_l),
                                     .so(so),
                                     .async_in(gdbginit_l),
                                     .gclk(gclk),
                                     .rclk(rclk),
                                     .arst_l(adbginit_l),
                                     .si(rst_sync_so),
                                     .se(se)
                                     );
`endif

endmodule // cluster_header