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// ***************************************************************************
// ***************************************************************************
// Copyright 2013(c) Analog Devices, Inc.
// Author: Lars-Peter Clausen <lars@metafoo.de>
//
// 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 Analog Devices, Inc. nor the names of its
// contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
// - The use of this software may or may not infringe the patent rights
// of one or more patent holders. This license does not release you
// from the requirement that you obtain separate licenses from these
// patent holders to use this software.
// - Use of the software either in source or binary form, must be run
// on or directly connected to an Analog Devices Inc. component.
//
// THIS SOFTWARE IS PROVIDED BY ANALOG DEVICES "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
// INCLUDING, BUT NOT LIMITED TO, NON-INFRINGEMENT, MERCHANTABILITY AND FITNESS FOR A
// PARTICULAR PURPOSE ARE DISCLAIMED.
//
// IN NO EVENT SHALL ANALOG DEVICES BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
// EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, INTELLECTUAL PROPERTY
// RIGHTS, 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 dmac_response_generator (
input clk,
input resetn,
input enable,
output reg enabled,
input [ID_WIDTH-1:0] request_id,
output reg [ID_WIDTH-1:0] response_id,
input sync_id,
input eot,
output resp_valid,
input resp_ready,
output resp_eot,
output [1:0] resp_resp
);
parameter ID_WIDTH = 3;
`include "inc_id.h"
`include "resp.h"
assign resp_resp = RESP_OKAY;
assign resp_eot = eot;
assign resp_valid = request_id != response_id && enabled;
// We have to wait for all responses before we can disable the response handler
always @(posedge clk) begin
if (resetn == 1'b0) begin
enabled <= 1'b0;
end else begin
if (enable)
enabled <= 1'b1;
else if (request_id == response_id)
enabled <= 1'b0;
end
end
always @(posedge clk) begin
if (resetn == 1'b0) begin
response_id <= 'h0;
end else begin
if ((resp_valid && resp_ready) ||
(sync_id && response_id != request_id))
response_id <= inc_id(response_id);
end
end
endmodule
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