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// ***************************************************************************
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// ***************************************************************************
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// Copyright 2014 - 2017 (c) Analog Devices, Inc. All rights reserved.
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//
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// In this HDL repository, there are many different and unique modules, consisting
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// of various HDL (Verilog or VHDL) components. The individual modules are
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// developed independently, and may be accompanied by separate and unique license
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// terms.
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//
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// The user should read each of these license terms, and understand the
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// freedoms and responsibilities that he or she has by using this source/core.
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//
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// This core is distributed in the hope that it will be useful, but WITHOUT ANY
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// WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
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// A PARTICULAR PURPOSE.
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//
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// Redistribution and use of source or resulting binaries, with or without modification
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// of this file, are permitted under one of the following two license terms:
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//
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// 1. The GNU General Public License version 2 as published by the
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// Free Software Foundation, which can be found in the top level directory
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// of this repository (LICENSE_GPL2), and also online at:
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// <https://www.gnu.org/licenses/old-licenses/gpl-2.0.html>
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//
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// OR
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//
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// 2. An ADI specific BSD license, which can be found in the top level directory
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// of this repository (LICENSE_ADIBSD), and also on-line at:
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// https://github.com/analogdevicesinc/hdl/blob/master/LICENSE_ADIBSD
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// This will allow to generate bit files and not release the source code,
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// as long as it attaches to an ADI device.
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//
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// ***************************************************************************
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// ***************************************************************************
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`timescale 1ns/100ps
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module axi_dacfifo_rd #(
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parameter AXI_DATA_WIDTH = 512,
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parameter AXI_SIZE = 2,
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parameter AXI_LENGTH = 15,
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parameter AXI_ADDRESS = 32'h00000000,
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parameter DAC_DATA_WIDTH = 64,
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parameter DAC_MEM_ADDRESS_WIDTH = 8) (
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// xfer last for read/write synchronization
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input axi_xfer_req,
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input [31:0] axi_last_raddr,
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input [ 7:0] axi_last_beats,
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// axi read address and read data channels
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input axi_clk,
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input axi_resetn,
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output reg axi_arvalid,
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output [ 3:0] axi_arid,
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output [ 1:0] axi_arburst,
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output axi_arlock,
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output [ 3:0] axi_arcache,
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output [ 2:0] axi_arprot,
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output [ 3:0] axi_arqos,
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output [ 7:0] axi_arlen,
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output [ 2:0] axi_arsize,
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output reg [31:0] axi_araddr,
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input axi_arready,
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input axi_rvalid,
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input [ 3:0] axi_rid,
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input [ 1:0] axi_rresp,
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input axi_rlast,
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input [(AXI_DATA_WIDTH-1):0] axi_rdata,
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output reg axi_rready,
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// axi status
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output reg axi_rerror,
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// DAC interface
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input [ 3:0] dma_last_beats,
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input dac_clk,
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input dac_rst,
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input dac_valid,
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output [(DAC_DATA_WIDTH-1):0] dac_data,
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output dac_xfer_out,
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output reg dac_dunf);
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`define max(a,b) {(a) > (b) ? (a) : (b)}
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`define min(a,b) {(a) < (b) ? (a) : (b)}
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localparam AXI_BYTE_WIDTH = AXI_DATA_WIDTH/8;
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localparam AXI_ARINCR = (AXI_LENGTH + 1) * AXI_BYTE_WIDTH;
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localparam MIN_WIDTH = `min(AXI_DATA_WIDTH, DAC_DATA_WIDTH);
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localparam MAX_WIDTH = `max(AXI_DATA_WIDTH, DAC_DATA_WIDTH);
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localparam MEM_RATIO = MAX_WIDTH/MIN_WIDTH;
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localparam AXI_BIGGER = (MAX_WIDTH == AXI_DATA_WIDTH) ? 1 : 0;
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localparam AXI_MEM_ADDRESS_WIDTH = (MEM_RATIO == 1) ? DAC_MEM_ADDRESS_WIDTH :
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(MEM_RATIO == 2) ? (DAC_MEM_ADDRESS_WIDTH + ((AXI_BIGGER == 1) ? (-1) : 1)) :
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(MEM_RATIO == 4) ? (DAC_MEM_ADDRESS_WIDTH + ((AXI_BIGGER == 1) ? (-2) : 2)) :
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(MEM_RATIO == 8) ? (DAC_MEM_ADDRESS_WIDTH + ((AXI_BIGGER == 1) ? (-3) : 3)) :
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(DAC_MEM_ADDRESS_WIDTH + ((AXI_BIGGER == 1) ? (-4) : 4));
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localparam AXI_BUF_THRESHOLD_HI = (AXI_BIGGER) ? (2 * (AXI_LENGTH+1)) : (2 * (AXI_LENGTH+1) * MEM_RATIO);
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localparam DAC_BUF_THRESHOLD_HI = (AXI_BIGGER) ? (2 * (AXI_LENGTH+1) * MEM_RATIO) : (2 * (AXI_LENGTH+1));
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localparam IDLE = 5'b00001;
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localparam XFER_STAGING = 5'b00010;
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localparam XFER_FULL_BURST = 5'b00100;
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localparam XFER_PARTIAL_BURST = 5'b01000;
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localparam XFER_END = 5'b10000;
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// internal registers
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reg axi_data_req = 1'b0;
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reg [ 4:0] axi_read_state = 5'b0;
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reg [(AXI_MEM_ADDRESS_WIDTH-1):0] axi_mem_waddr = 'd0;
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(* dont_touch = "true" *) reg [(AXI_MEM_ADDRESS_WIDTH-1):0] axi_mem_laddr = 'd0;
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reg [(DAC_MEM_ADDRESS_WIDTH-1):0] axi_mem_waddr_g = 'd0;
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(* dont_touch = "true" *) reg axi_mem_laddr_toggle = 1'b0;
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reg [(DAC_MEM_ADDRESS_WIDTH-1):0] axi_mem_raddr = 'd0;
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reg [(DAC_MEM_ADDRESS_WIDTH-1):0] axi_mem_raddr_m1 = 'd0;
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reg [(DAC_MEM_ADDRESS_WIDTH-1):0] axi_mem_raddr_m2 = 'd0;
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reg [(AXI_MEM_ADDRESS_WIDTH-1):0] axi_mem_addr_diff = 'd0;
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reg [31:0] axi_araddr_prev = 'd0;
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reg [(DAC_MEM_ADDRESS_WIDTH-1):0] dac_mem_raddr = 'd0;
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reg [(DAC_MEM_ADDRESS_WIDTH-1):0] dac_mem_raddr_g = 'd0;
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reg [(DAC_MEM_ADDRESS_WIDTH-1):0] dac_mem_waddr = 'd0;
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reg [(DAC_MEM_ADDRESS_WIDTH-1):0] dac_mem_waddr_m1 = 'd0;
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reg [(DAC_MEM_ADDRESS_WIDTH-1):0] dac_mem_waddr_m2 = 'd0;
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reg [(DAC_MEM_ADDRESS_WIDTH-1):0] dac_mem_laddr = 'd0;
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reg [ 3:0] dac_mem_laddr_toggle_m = 4'd0;
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reg [(DAC_MEM_ADDRESS_WIDTH-1):0] dac_mem_laddr_b = 'd0;
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reg dac_mem_valid = 1'b0;
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reg dac_mem_enable = 1'b0;
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reg [ 2:0] dac_xfer_req_m = 3'b0;
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reg [ 3:0] dac_last_beats = 4'b0;
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reg [ 3:0] dac_last_beats_m = 4'b0;
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// internal signals
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wire axi_fifo_reset_s;
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wire axi_dvalid_s;
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wire axi_dlast_s;
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wire [ AXI_MEM_ADDRESS_WIDTH:0] axi_mem_addr_diff_s;
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wire [(AXI_MEM_ADDRESS_WIDTH-1):0] axi_mem_raddr_s;
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wire [(DAC_MEM_ADDRESS_WIDTH-1):0] axi_mem_waddr_s;
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wire [(DAC_MEM_ADDRESS_WIDTH-1):0] axi_mem_laddr_s;
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wire [(DAC_MEM_ADDRESS_WIDTH-1):0] axi_mem_waddr_b2g_s;
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wire [(DAC_MEM_ADDRESS_WIDTH-1):0] axi_mem_raddr_m2_g2b_s;
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wire [(DAC_MEM_ADDRESS_WIDTH-1):0] dac_mem_raddr_b2g_s;
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wire [(DAC_MEM_ADDRESS_WIDTH-1):0] dac_mem_waddr_m2_g2b_s;
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wire [ DAC_MEM_ADDRESS_WIDTH:0] dac_mem_addr_diff_s;
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wire [(DAC_MEM_ADDRESS_WIDTH-1):0] dac_mem_laddr_s;
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// Asymmetric memory to transfer data from AXI_MM interface to DAC FIFO
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// interface
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ad_mem_asym #(
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.A_ADDRESS_WIDTH (AXI_MEM_ADDRESS_WIDTH),
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.A_DATA_WIDTH (AXI_DATA_WIDTH),
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.B_ADDRESS_WIDTH (DAC_MEM_ADDRESS_WIDTH),
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.B_DATA_WIDTH (DAC_DATA_WIDTH))
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i_mem_asym (
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.clka (axi_clk),
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.wea (axi_dvalid_s),
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.addra (axi_mem_waddr),
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.dina (axi_rdata),
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.clkb (dac_clk),
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.reb (1'b1),
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.addrb (dac_mem_raddr),
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.doutb (dac_data));
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// reset signals
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assign axi_fifo_reset_s = (axi_resetn == 1'b0) || (axi_xfer_req == 1'b0);
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assign dac_fifo_reset_s = (dac_rst == 1'b1) || (dac_xfer_req_m[2] == 1'b0);
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// FSM to generate the all the AXI Read transactions
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always @(posedge axi_clk) begin
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if (axi_fifo_reset_s == 1'b1) begin
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axi_read_state <= IDLE;
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end else begin
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case (axi_read_state)
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IDLE : begin
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if (axi_data_req == 1'b1) begin
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axi_read_state <= XFER_STAGING;
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end else begin
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axi_read_state <= IDLE;
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end
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end
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XFER_STAGING : begin
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if (axi_araddr + AXI_ARINCR <= axi_last_raddr) begin
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axi_read_state <= XFER_FULL_BURST;
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end else begin
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axi_read_state <= XFER_PARTIAL_BURST;
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end
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end
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XFER_FULL_BURST : begin
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if (axi_rready && axi_rvalid && axi_rlast) begin
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if (axi_araddr_prev == axi_last_raddr) begin
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axi_read_state <= XFER_END;
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end else begin
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axi_read_state <= IDLE;
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end
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end else begin
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axi_read_state <= XFER_FULL_BURST;
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end
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end
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XFER_PARTIAL_BURST : begin
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if (axi_rready && axi_rvalid && axi_rlast) begin
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axi_read_state <= XFER_END;
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end else begin
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axi_read_state <= XFER_PARTIAL_BURST;
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end
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end
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XFER_END : begin
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axi_read_state <= IDLE;
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end
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default : begin
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axi_read_state <= IDLE;
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end
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endcase
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end
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end
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// AXI read address channel
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always @(posedge axi_clk) begin
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if (axi_fifo_reset_s == 1'b1) begin
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axi_arvalid <= 'd0;
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axi_araddr <= AXI_ADDRESS;
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axi_araddr_prev <= AXI_ADDRESS;
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end else begin
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if (axi_arvalid == 1'b1) begin
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if (axi_arready == 1'b1) begin
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axi_arvalid <= 1'b0;
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end
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end else begin
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if (axi_read_state == XFER_STAGING) begin
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axi_arvalid <= 1'b1;
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end
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end
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// AXI read address generation
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if ((axi_arvalid == 1'b1) && (axi_arready == 1'b1)) begin
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axi_araddr <= (axi_read_state == XFER_FULL_BURST) ? (axi_araddr + AXI_ARINCR) :
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(axi_read_state == XFER_PARTIAL_BURST) ? AXI_ADDRESS : axi_araddr;
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axi_araddr_prev <= axi_araddr;
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end
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end
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end
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assign axi_arid = 4'b0000;
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assign axi_arburst = 2'b01;
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assign axi_arlock = 1'b0;
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assign axi_arcache = 4'b0010;
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assign axi_arprot = 3'b000;
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assign axi_arqos = 4'b0000;
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assign axi_arlen = (axi_read_state == XFER_FULL_BURST) ? AXI_LENGTH :
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(axi_read_state == XFER_PARTIAL_BURST) ? axi_last_beats : AXI_LENGTH;
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assign axi_arsize = AXI_SIZE;
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// AXI read data channel
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assign axi_dvalid_s = axi_rvalid & axi_rready & axi_xfer_req;
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assign axi_dlast_s = (axi_araddr_prev == axi_last_raddr) ? axi_rlast : 0;
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always @(posedge axi_clk) begin
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if (axi_fifo_reset_s == 1'b1) begin
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axi_rready <= 1'b0;
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axi_rerror <= 'd0;
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end else begin
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axi_rready <= axi_rvalid;
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axi_rerror <= axi_rvalid & axi_rresp[1];
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end
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end
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// ASYNC MEM write control
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always @(posedge axi_clk) begin
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if (axi_fifo_reset_s == 1'b1) begin
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axi_mem_waddr <= 'd0;
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axi_mem_waddr_g <= 'd0;
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axi_mem_laddr <= {AXI_MEM_ADDRESS_WIDTH{1'b1}};
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axi_mem_laddr_toggle <= 0;
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end else begin
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if (axi_dvalid_s == 1'b1) begin
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axi_mem_waddr <= axi_mem_waddr + 1'b1;
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if (axi_dlast_s == 1'b1) begin
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axi_mem_laddr <= axi_mem_waddr;
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axi_mem_laddr_toggle <= ~axi_mem_laddr_toggle;
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end
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end
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axi_mem_waddr_g <= axi_mem_waddr_b2g_s;
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end
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end
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ad_b2g # (
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.DATA_WIDTH(DAC_MEM_ADDRESS_WIDTH)
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) i_axi_mem_waddr_b2g (
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.din (axi_mem_waddr_s),
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.dout (axi_mem_waddr_b2g_s));
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assign axi_mem_raddr_s = (MEM_RATIO == 1) ? axi_mem_raddr :
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(MEM_RATIO == 2) ? ((AXI_BIGGER == 1) ? axi_mem_raddr[(DAC_MEM_ADDRESS_WIDTH-1):1] : {axi_mem_raddr, 1'b0}) :
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(MEM_RATIO == 4) ? ((AXI_BIGGER == 1) ? axi_mem_raddr[(DAC_MEM_ADDRESS_WIDTH-1):2] : {axi_mem_raddr, 2'b0}) :
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(MEM_RATIO == 8) ? ((AXI_BIGGER == 1) ? axi_mem_raddr[(DAC_MEM_ADDRESS_WIDTH-1):3] : {axi_mem_raddr, 3'b0}) :
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((AXI_BIGGER == 1) ? axi_mem_raddr[(DAC_MEM_ADDRESS_WIDTH-1):4] : {axi_mem_raddr, 4'b0});
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assign axi_mem_waddr_s = (MEM_RATIO == 1) ? axi_mem_waddr :
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(MEM_RATIO == 2) ? ((AXI_BIGGER == 1) ? {axi_mem_waddr, 1'b0} : axi_mem_waddr[AXI_MEM_ADDRESS_WIDTH-1:1]) :
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(MEM_RATIO == 4) ? ((AXI_BIGGER == 1) ? {axi_mem_waddr, 2'b0} : axi_mem_waddr[AXI_MEM_ADDRESS_WIDTH-1:2]) :
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(MEM_RATIO == 8) ? ((AXI_BIGGER == 1) ? {axi_mem_waddr, 3'b0} : axi_mem_waddr[AXI_MEM_ADDRESS_WIDTH-1:3]) :
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((AXI_BIGGER == 1) ? {axi_mem_waddr, 4'b0} : axi_mem_waddr[AXI_MEM_ADDRESS_WIDTH-1:4]);
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assign axi_mem_laddr_s = (MEM_RATIO == 1) ? axi_mem_laddr :
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(MEM_RATIO == 2) ? ((AXI_BIGGER == 1) ? {axi_mem_laddr, 1'b0} : axi_mem_laddr[AXI_MEM_ADDRESS_WIDTH-1:1]) :
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(MEM_RATIO == 4) ? ((AXI_BIGGER == 1) ? {axi_mem_laddr, 2'b0} : axi_mem_laddr[AXI_MEM_ADDRESS_WIDTH-1:2]) :
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(MEM_RATIO == 8) ? ((AXI_BIGGER == 1) ? {axi_mem_laddr, 3'b0} : axi_mem_laddr[AXI_MEM_ADDRESS_WIDTH-1:3]) :
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((AXI_BIGGER == 1) ? {axi_mem_laddr, 4'b0} : axi_mem_laddr[AXI_MEM_ADDRESS_WIDTH-1:4]);
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assign axi_mem_addr_diff_s = {1'b1, axi_mem_waddr} - axi_mem_raddr_s;
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always @(posedge axi_clk) begin
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if (axi_fifo_reset_s == 1'b1) begin
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axi_mem_addr_diff <= 'd0;
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axi_mem_raddr <= 'd0;
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axi_mem_raddr_m1 <= 'd0;
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axi_mem_raddr_m2 <= 'd0;
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axi_data_req <= 'd0;
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end else begin
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axi_mem_raddr_m1 <= dac_mem_raddr_g;
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axi_mem_raddr_m2 <= axi_mem_raddr_m1;
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axi_mem_raddr <= axi_mem_raddr_m2_g2b_s;
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axi_mem_addr_diff <= axi_mem_addr_diff_s[AXI_MEM_ADDRESS_WIDTH-1:0];
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// requesting AXI read access from the memory, if there is enough space
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// for a full burst in the async buffer
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if (axi_mem_addr_diff >= AXI_BUF_THRESHOLD_HI) begin
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axi_data_req <= 1'b0;
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end else begin
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||||
axi_data_req <= 1'b1;
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end
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||||
end
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||||
end
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||||
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ad_g2b #(
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.DATA_WIDTH(DAC_MEM_ADDRESS_WIDTH)
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) i_axi_mem_raddr_m2_g2b (
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.din (axi_mem_raddr_m2),
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.dout (axi_mem_raddr_m2_g2b_s));
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||||
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||||
// CDC for xfer_req signal
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||||
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always @(posedge dac_clk) begin
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||||
if (dac_rst == 1'b1) begin
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||||
dac_xfer_req_m <= 3'b0;
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end else begin
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||||
dac_xfer_req_m <= {dac_xfer_req_m[1:0], axi_xfer_req};
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||||
end
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||||
end
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||||
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assign dac_xfer_out = dac_xfer_req_m[2] & dac_mem_valid;
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||||
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||||
// CDC for write addresses from the DDRx clock domain
|
||||
always @(posedge dac_clk) begin
|
||||
if (dac_fifo_reset_s == 1'b1) begin
|
||||
dac_mem_waddr <= 'b0;
|
||||
dac_mem_waddr_m1 <= 'b0;
|
||||
dac_mem_waddr_m2 <= 'b0;
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||||
dac_mem_laddr_toggle_m <= 4'b0;
|
||||
dac_mem_laddr <= 'b0;
|
||||
end else begin
|
||||
dac_mem_waddr_m1 <= axi_mem_waddr_g;
|
||||
dac_mem_waddr_m2 <= dac_mem_waddr_m1;
|
||||
dac_mem_waddr <= dac_mem_waddr_m2_g2b_s;
|
||||
dac_mem_laddr_toggle_m <= {dac_mem_laddr_toggle_m[2:0], axi_mem_laddr_toggle};
|
||||
dac_mem_laddr <= (dac_mem_laddr_toggle_m[2] ^ dac_mem_laddr_toggle_m[1]) ?
|
||||
axi_mem_laddr_s :
|
||||
dac_mem_laddr;
|
||||
end
|
||||
end
|
||||
|
||||
assign dac_laddr_wea = dac_mem_laddr_toggle_m[3] ^ dac_mem_laddr_toggle_m[2];
|
||||
assign dac_laddr_rea = ((dac_mem_raddr == dac_mem_laddr_b) &&
|
||||
(dac_xfer_out == 1'b1)) ? 1'b1 :1'b0;
|
||||
|
||||
axi_dacfifo_address_buffer #(
|
||||
.ADDRESS_WIDTH (4),
|
||||
.DATA_WIDTH (DAC_MEM_ADDRESS_WIDTH))
|
||||
i_laddress_buffer (
|
||||
.clk (dac_clk),
|
||||
.rst (dac_fifo_reset_s),
|
||||
.wea (dac_laddr_wea),
|
||||
.din (dac_mem_laddr),
|
||||
.rea (dac_laddr_rea),
|
||||
.dout (dac_mem_laddr_s));
|
||||
|
||||
ad_g2b #(
|
||||
.DATA_WIDTH(DAC_MEM_ADDRESS_WIDTH)
|
||||
) i_dac_mem_waddr_m2_g2b (
|
||||
.din (dac_mem_waddr_m2),
|
||||
.dout (dac_mem_waddr_m2_g2b_s));
|
||||
|
||||
assign dac_mem_addr_diff_s = {1'b1, dac_mem_waddr} - dac_mem_raddr;
|
||||
|
||||
// ASYNC MEM read control
|
||||
|
||||
always @(posedge dac_clk) begin
|
||||
if (dac_fifo_reset_s == 1'b1) begin
|
||||
dac_mem_enable <= 1'b0;
|
||||
dac_mem_valid <= 1'b0;
|
||||
end else begin
|
||||
if (dac_mem_dunf_s == 1'b1) begin
|
||||
dac_mem_enable <= 1'b0;
|
||||
end else if (dac_mem_addr_diff_s[(DAC_MEM_ADDRESS_WIDTH-1):0] >= DAC_BUF_THRESHOLD_HI) begin
|
||||
dac_mem_enable <= 1'b1;
|
||||
end
|
||||
dac_mem_valid <= (dac_mem_enable) ? dac_valid : 1'b0;
|
||||
end
|
||||
end
|
||||
|
||||
// CDC for the dma_last_beats
|
||||
|
||||
always @(posedge dac_clk) begin
|
||||
if (dac_fifo_reset_s == 1'b1) begin
|
||||
dac_last_beats <= 4'b0;
|
||||
dac_last_beats_m <= 4'b0;
|
||||
end else begin
|
||||
dac_last_beats_m <= dma_last_beats;
|
||||
dac_last_beats <= dac_last_beats_m;
|
||||
end
|
||||
end
|
||||
|
||||
// If the MEM_RATIO is grater than one, it can happen that not all the DAC beats from
|
||||
// an AXI beat are valid. In this case the invalid data is dropped.
|
||||
// The axi_dlast indicates the last AXI beat. The valid number of DAC beats on the last AXI beat
|
||||
// commes from the AXI write module. (axi_dacfifo_wr.v)
|
||||
|
||||
always @(posedge dac_clk) begin
|
||||
if (dac_fifo_reset_s == 1'b1) begin
|
||||
dac_mem_raddr <= 'd0;
|
||||
dac_mem_laddr_b <= 'd0;
|
||||
dac_mem_raddr_g <= 'd0;
|
||||
end else begin
|
||||
dac_mem_laddr_b <= dac_mem_laddr_s;
|
||||
if (dac_mem_valid == 1'b1) begin
|
||||
if ((dac_last_beats != 0) &&
|
||||
(dac_mem_raddr == (dac_mem_laddr_b + dac_last_beats - 1))) begin
|
||||
dac_mem_raddr <= dac_mem_raddr + (MEM_RATIO - (dac_last_beats - 1));
|
||||
end else begin
|
||||
dac_mem_raddr <= dac_mem_raddr + 1'b1;
|
||||
end
|
||||
end
|
||||
dac_mem_raddr_g <= dac_mem_raddr_b2g_s;
|
||||
end
|
||||
end
|
||||
|
||||
ad_b2g # (
|
||||
.DATA_WIDTH(DAC_MEM_ADDRESS_WIDTH)
|
||||
) i_dac_mem_raddr_b2g (
|
||||
.din (dac_mem_raddr),
|
||||
.dout (dac_mem_raddr_b2g_s));
|
||||
|
||||
// underflow generation, there is no overflow
|
||||
|
||||
assign dac_mem_dunf_s = (dac_mem_addr_diff_s[(DAC_MEM_ADDRESS_WIDTH-1):0] == 0) ? 1'b1 : 1'b0;
|
||||
|
||||
always @(posedge dac_clk) begin
|
||||
if(dac_fifo_reset_s == 1'b1) begin
|
||||
dac_dunf <= 1'b0;
|
||||
end else begin
|
||||
dac_dunf <= dac_mem_dunf_s;
|
||||
end
|
||||
end
|
||||
|
||||
endmodule
|
||||
|
||||
// ***************************************************************************
|
||||
// ***************************************************************************
|
||||
Reference in New Issue
Block a user