pluto_hdl_adi/library/axi_dmac/data_mover.v

273 lines
8.2 KiB
Coq
Raw Normal View History

// ***************************************************************************
// ***************************************************************************
// Copyright 2014 - 2017 (c) Analog Devices, Inc. All rights reserved.
//
// In this HDL repository, there are many different and unique modules, consisting
// of various HDL (Verilog or VHDL) components. The individual modules are
// developed independently, and may be accompanied by separate and unique license
// terms.
//
// The user should read each of these license terms, and understand the
2018-03-14 14:45:47 +00:00
// freedoms and responsibilities that he or she has by using this source/core.
//
// This core 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.
//
// Redistribution and use of source or resulting binaries, with or without modification
// of this file, are permitted under one of the following two license terms:
//
// 1. The GNU General Public License version 2 as published by the
// Free Software Foundation, which can be found in the top level directory
// of this repository (LICENSE_GPL2), and also online at:
// <https://www.gnu.org/licenses/old-licenses/gpl-2.0.html>
//
// OR
//
// 2. An ADI specific BSD license, which can be found in the top level directory
// of this repository (LICENSE_ADIBSD), and also on-line at:
// https://github.com/analogdevicesinc/hdl/blob/master/LICENSE_ADIBSD
// This will allow to generate bit files and not release the source code,
// as long as it attaches to an ADI device.
//
// ***************************************************************************
// ***************************************************************************
`timescale 1ns/100ps
module data_mover #(
parameter ID_WIDTH = 3,
parameter DATA_WIDTH = 64,
parameter BEATS_PER_BURST_WIDTH = 4,
parameter ALLOW_ABORT = 0
) (
input clk,
input resetn,
input [ID_WIDTH-1:0] request_id,
output [ID_WIDTH-1:0] response_id,
input eot,
output rewind_req_valid,
input rewind_req_ready,
output [ID_WIDTH+3-1:0] rewind_req_data,
output reg bl_valid = 'b0,
input bl_ready,
output reg [BEATS_PER_BURST_WIDTH-1:0] measured_last_burst_length,
output block_descr_to_dst,
output [ID_WIDTH-1:0] source_id,
output source_eot,
output xfer_req,
output s_axi_ready,
input s_axi_valid,
input [DATA_WIDTH-1:0] s_axi_data,
input s_axi_last,
input s_axi_sync,
output m_axi_valid,
output [DATA_WIDTH-1:0] m_axi_data,
output m_axi_last,
output m_axi_partial_burst,
input req_valid,
output req_ready,
input [BEATS_PER_BURST_WIDTH-1:0] req_last_burst_length,
input req_sync_transfer_start,
input req_xlast
);
localparam BEAT_COUNTER_MAX = {BEATS_PER_BURST_WIDTH{1'b1}};
`include "inc_id.vh"
reg [BEATS_PER_BURST_WIDTH-1:0] last_burst_length = 'h00;
reg [BEATS_PER_BURST_WIDTH-1:0] beat_counter = 'h00;
reg [BEATS_PER_BURST_WIDTH-1:0] beat_counter_minus_one = 'h0;
reg [ID_WIDTH-1:0] id = 'h00;
reg [ID_WIDTH-1:0] id_next = 'h00;
reg pending_burst = 1'b0;
reg active = 1'b0;
reg last_eot = 1'b0;
reg last_non_eot = 1'b0;
reg needs_sync = 1'b0;
wire has_sync = ~needs_sync | s_axi_sync;
wire s_axi_sync_valid = has_sync & s_axi_valid;
wire transfer_abort_s;
wire last_load;
wire last;
wire early_tlast;
assign xfer_req = active;
assign response_id = id;
assign source_id = id;
assign source_eot = eot || early_tlast;
assign last = eot ? last_eot : last_non_eot;
assign s_axi_ready = (pending_burst & active) & ~transfer_abort_s;
assign m_axi_valid = s_axi_sync_valid & s_axi_ready;
assign m_axi_data = s_axi_data;
assign m_axi_last = last || early_tlast;
assign m_axi_partial_burst = early_tlast;
assign block_descr_to_dst = transfer_abort_s;
generate if (ALLOW_ABORT == 1) begin
wire programmed_last;
reg transfer_abort = 1'b0;
reg req_xlast_d = 1'b0;
reg [1:0] transfer_id = 2'b0;
assign programmed_last = (last == 1'b1 && eot == 1'b1 && req_xlast_d == 1'b1);
/*
* A 'last' on the external interface indicates the end of an packet. If such a
* 'last' indicator is observed before the end of the current transfer stop
* accepting data on the external interface until a new descriptor is
* received that is the first segment of a transfer.
*/
always @(posedge clk) begin
if (resetn == 1'b0) begin
transfer_abort <= 1'b0;
end else if (req_valid == 1'b1 && req_ready == 1'b1 && req_xlast_d == 1'b1) begin
transfer_abort <= 1'b0;
end else if (m_axi_valid == 1'b1) begin
if (programmed_last == 1'b1) begin
transfer_abort <= 1'b0;
end else if (s_axi_last == 1'b1) begin
transfer_abort <= 1'b1;
end
end
end
always @(posedge clk) begin
if (req_ready == 1'b1 && req_valid == 1'b1) begin
req_xlast_d <= req_xlast;
end
end
assign transfer_abort_s = transfer_abort;
assign early_tlast = (s_axi_ready == 1'b1) && (m_axi_valid == 1'b1) &&
(s_axi_last == 1'b1) && (programmed_last == 1'b0);
assign rewind_req_valid = early_tlast;
assign rewind_req_data = {transfer_id,req_xlast_d,id_next};
// The width of the id must fit the number of transfers that can be in flight
// in the burst memory
always @(posedge clk) begin
if (resetn == 1'b0) begin
transfer_id <= 2'b0;
end else if (req_valid == 1'b1 && req_ready == 1'b1) begin
transfer_id <= transfer_id + 1'b1;
end
end
end else begin
assign transfer_abort_s = 1'b0;
assign early_tlast = 1'b0;
assign rewind_req_valid = 1'b0;
assign rewind_req_data = 'h0;
end endgenerate
/*
* If req_sync_transfer_start is set all incoming beats will be skipped until
* one has s_axi_sync set. This will be the first beat that is passsed through.
*/
always @(posedge clk) begin
if (req_ready == 1'b1) begin
needs_sync <= req_sync_transfer_start;
end else if (m_axi_valid == 1'b1) begin
needs_sync <= 1'b0;
end
end
// If we want to support zero delay between transfers we have to assert
// req_ready on the same cycle on which the last load happens.
// In case early tlast happens accept the new descriptor only when the rewind
// request got accepted.
// In case the data mover is not active accept a new descriptor only when the
// upstream logic incremented its id (pending_burst is set).
assign last_load = m_axi_valid && last_eot && eot;
assign req_ready = (last_load && ~early_tlast) ||
((~active && ~transfer_abort_s) && pending_burst) ||
(transfer_abort_s && rewind_req_ready);
always @(posedge clk) begin
if (req_ready) begin
last_eot <= req_last_burst_length == 'h0;
last_non_eot <= 1'b0;
beat_counter <= 'h1;
end else if (m_axi_valid == 1'b1) begin
last_eot <= beat_counter == last_burst_length;
last_non_eot <= beat_counter == BEAT_COUNTER_MAX;
beat_counter <= beat_counter + 1'b1;
end
end
always @(posedge clk) begin
if (req_ready)
last_burst_length <= req_last_burst_length;
end
always @(posedge clk) begin
if (req_ready) begin
beat_counter_minus_one <= 'h0;
end else if (m_axi_valid == 1'b1) begin
beat_counter_minus_one <= beat_counter;
end
end
always @(posedge clk) begin
if (last_load || early_tlast) begin
bl_valid <= 1'b1;
measured_last_burst_length <= beat_counter_minus_one;
end else if (bl_ready) begin
bl_valid <= 1'b0;
end
end
always @(posedge clk) begin
if (resetn == 1'b0) begin
active <= 1'b0;
end else if (req_valid == 1'b1 && req_ready == 1'b1) begin
active <= 1'b1;
end else if (last_load == 1'b1) begin
active <= 1'b0;
end
end
always @(*)
begin
if (m_axi_valid == 1'b1 && (last == 1'b1 || early_tlast == 1'b1))
id_next <= inc_id(id);
else
id_next <= id;
end
always @(posedge clk) begin
if (resetn == 1'b0) begin
id <= 'h0;
end else begin
id <= id_next;
end
end
always @(posedge clk) begin
pending_burst <= id_next != request_id;
end
endmodule