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| -rw-r--r-- | extra/reset_replicator.v | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/extra/reset_replicator.v b/extra/reset_replicator.v new file mode 100644 index 0000000..ccb704b --- /dev/null +++ b/extra/reset_replicator.v @@ -0,0 +1,93 @@ +//====================================================================== +// +// reset_replicator.v +// ------------------ +// +// Generates localized copies of the system-wide reset so that each core can +// have its own copy. This way there's more room for the placer to do its job. +// +// Author: Pavel Shatov +// Copyright (c) 2016, 2018-2019 NORDUnet A/S All rights reserved. +// +// Redistribution and use in source and binary forms, with or without +// modification, are permitted provided that the following conditions +// are met: +// - Redistributions of source code must retain the above copyright +// notice, this list of conditions and the following disclaimer. +// +// - Redistributions in binary form must reproduce the above copyright +// notice, this list of conditions and the following disclaimer in the +// documentation and/or other materials provided with the distribution. +// +// - Neither the name of the NORDUnet nor the names of its contributors may +// be used to endorse or promote products derived from this software +// without specific prior written permission. +// +// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS +// IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED +// TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A +// PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +// HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED +// TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR +// PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF +// LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING +// NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS +// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. +// +//====================================================================== + +module reset_replicator +( + sys_clk_in, + sys_rst_n_in, + sys_rst_n_out +); + + // + // Parameters + // + parameter integer SHREG_WIDTH = 8; + parameter integer FANOUT_WIDTH = 8; + + // + // Ports + // + input sys_clk_in; + input sys_rst_n_in; + output [FANOUT_WIDTH-1:0] sys_rst_n_out; + + // + // Internals + // + wire [FANOUT_WIDTH-1:0] sys_rst_int; + + // + // Localized Reset Replication + // + genvar i; + generate for (i=0; i<FANOUT_WIDTH; i=i+1) + // + begin : gen_sys_rst_n_out + // + LUT1 #(.INIT(2'b01)) LUT1_inst + ( .I0(sys_rst_n_in), + .O(sys_rst_int[i]) + ); + // + (* SHREG_EXTRACT="NO" *) + (* EQUIVALENT_REGISTER_REMOVAL="NO" *) + reg [SHREG_WIDTH-1:0] sys_rst_n_shreg_copy = {SHREG_WIDTH{1'b0}}; + // + always @(posedge sys_clk_in or posedge sys_rst_int[i]) + // + if (sys_rst_int[i]) sys_rst_n_shreg_copy <= {SHREG_WIDTH{1'b0}}; + else sys_rst_n_shreg_copy <= {sys_rst_n_shreg_copy[SHREG_WIDTH-2:0], 1'b1}; + // + assign sys_rst_n_out[i] = sys_rst_n_shreg_copy[SHREG_WIDTH-1]; + // + end + // + endgenerate + +endmodule |