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91 lines
2.7 KiB
Verilog
91 lines
2.7 KiB
Verilog
/*
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########################################################################
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Generic Clock Domain Crossing Block
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########################################################################
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*/
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module fifo_cdc (/*AUTOARG*/
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// Outputs
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wait_out, access_out, packet_out,
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// Inputs
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clk_in, clk_out, reset, access_in, packet_in, wait_in
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);
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parameter FD = 16; //minimum depth
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parameter AW = $clog2(FD);
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parameter DW = 104;
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/********************************/
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/*Clocks/reset */
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/********************************/
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input clk_in;
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input clk_out;
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input reset;
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/********************************/
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/*Input Packet*/
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/********************************/
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input access_in;
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input [DW-1:0] packet_in;
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output wait_out;
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/********************************/
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/*Register RD/WR Packet to ERX*/
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/********************************/
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output access_out;
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output [DW-1:0] packet_out;
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input wait_in;
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//Local wires
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wire wr_en;
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wire rd_en;
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wire empty;
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wire full;
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reg access_out;
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assign wr_en = access_in & ~full;
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assign rd_en = ~empty & ~wait_in;
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assign wait_out = full;
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//Keep access high until "acknowledge"
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always @ (posedge clk_out or posedge reset)
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if(reset)
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access_out <=1'b0;
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else if(~wait_in)
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access_out <=rd_en;
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//Read response fifo (from master)
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fifo_async #(.DW(DW), .AW(5)) fifo(
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.prog_full (),
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.full (full),
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// Outputs
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.dout (packet_out[DW-1:0]),
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.empty (empty),
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.valid (),
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// Inputs
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.reset (reset),
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.wr_clk (clk_in),
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.rd_clk (clk_out),
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.wr_en (wr_en),
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.din (packet_in[DW-1:0]),
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.rd_en (rd_en)
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);
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endmodule // fifo_cdc
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/*
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Copyright (C) 2013 Adapteva, Inc.
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Contributed by Andreas Olofsson <andreas@adapteva.com>
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This program is free software: you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation, either version 3 of the License, or
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(at your option) any later version.This program is distributed in the hope
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that it will be useful,but WITHOUT ANY WARRANTY; without even the implied
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warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details. You should have received a copy
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of the GNU General Public License along with this program (see the file
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COPYING). If not, see <http://www.gnu.org/licenses/>.
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*/
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