pluto_hdl_adi/library/axi_dmac/address_generator.v

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// ***************************************************************************
// ***************************************************************************
// Copyright 2013(c) Analog Devices, Inc.
//
// 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_address_generator (
input clk,
input resetn,
input req_valid,
output reg req_ready,
input [31:C_BYTES_PER_BEAT_WIDTH] req_address,
input [C_BEATS_PER_BURST_WIDTH-1:0] req_last_burst_length,
output reg [C_ID_WIDTH-1:0] id,
input [C_ID_WIDTH-1:0] request_id,
input sync_id,
input eot,
input enable,
input pause,
output reg enabled,
input addr_ready,
output reg addr_valid,
output [31:0] addr,
output [ 7:0] len,
output [ 2:0] size,
output [ 1:0] burst,
output [ 2:0] prot,
output [ 3:0] cache
);
parameter C_ID_WIDTH = 3;
parameter C_DMA_DATA_WIDTH = 64;
parameter C_BEATS_PER_BURST_WIDTH = 4;
parameter C_BYTES_PER_BEAT_WIDTH = $clog2(C_DMA_DATA_WIDTH/8);
localparam MAX_BEATS_PER_BURST = 2**(C_BEATS_PER_BURST_WIDTH);
`include "inc_id.h"
assign burst = 2'b01;
assign prot = 3'b000;
assign cache = 4'b0011;
assign len = length;
assign size = $clog2(C_DMA_DATA_WIDTH/8);
reg [7:0] length = 'h0;
reg [31-C_BYTES_PER_BEAT_WIDTH:0] address = 'h00;
reg [C_BEATS_PER_BURST_WIDTH-1:0] last_burst_len = 'h00;
assign addr = {address, {C_BYTES_PER_BEAT_WIDTH{1'b0}}};
reg addr_valid_d1;
reg last = 1'b0;
// If we already asserted addr_valid we have to wait until it is accepted before
// we can disable the address generator.
always @(posedge clk) begin
if (resetn == 1'b0) begin
enabled <= 1'b0;
end else begin
if (enable)
enabled <= 1'b1;
else if (~addr_valid)
enabled <= 1'b0;
end
end
always @(posedge clk) begin
if (addr_valid == 1'b0) begin
if (eot == 1'b1)
length <= req_last_burst_length;
else
length <= MAX_BEATS_PER_BURST - 1;
end
end
always @(posedge clk) begin
if (resetn == 1'b0) begin
last <= 1'b0;
end else if (addr_valid == 1'b0) begin
last <= eot;
end
end
always @(posedge clk) begin
if (resetn == 1'b0) begin
address <= 'h00;
last_burst_len <= 'h00;
req_ready <= 1'b1;
addr_valid <= 1'b0;
end else begin
if (~enabled) begin
req_ready <= 1'b1;
end else if (req_ready) begin
if (req_valid && enable) begin
address <= req_address;
req_ready <= 1'b0;
end
end else begin
if (addr_valid && addr_ready) begin
address <= address + MAX_BEATS_PER_BURST;
addr_valid <= 1'b0;
if (last)
req_ready <= 1'b1;
end else if (id != request_id && enable) begin
addr_valid <= 1'b1;
end
end
end
end
always @(posedge clk) begin
if (resetn == 1'b0) begin
id <='h0;
addr_valid_d1 <= 1'b0;
end else begin
addr_valid_d1 <= addr_valid;
if ((addr_valid && ~addr_valid_d1) ||
(sync_id && id != request_id))
id <= inc_id(id);
end
end
endmodule