139 lines
4.8 KiB
Verilog
Executable File
139 lines
4.8 KiB
Verilog
Executable File
// ***************************************************************************
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// ***************************************************************************
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// Copyright 2011(c) Analog Devices, Inc.
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//
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// All rights reserved.
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//
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// Redistribution and use in source and binary forms, with or without modification,
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// are permitted provided that the following conditions are met:
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// - Redistributions of source code must retain the above copyright
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// notice, this list of conditions and the following disclaimer.
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// - Redistributions in binary form must reproduce the above copyright
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// notice, this list of conditions and the following disclaimer in
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// the documentation and/or other materials provided with the
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// distribution.
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// - Neither the name of Analog Devices, Inc. nor the names of its
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// contributors may be used to endorse or promote products derived
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// from this software without specific prior written permission.
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// - The use of this software may or may not infringe the patent rights
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// of one or more patent holders. This license does not release you
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// from the requirement that you obtain separate licenses from these
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// patent holders to use this software.
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// - Use of the software either in source or binary form, must be run
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// on or directly connected to an Analog Devices Inc. component.
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//
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// THIS SOFTWARE IS PROVIDED BY ANALOG DEVICES "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
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// INCLUDING, BUT NOT LIMITED TO, NON-INFRINGEMENT, MERCHANTABILITY AND FITNESS FOR A
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// PARTICULAR PURPOSE ARE DISCLAIMED.
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//
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// IN NO EVENT SHALL ANALOG DEVICES BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
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// EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, INTELLECTUAL PROPERTY
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// RIGHTS, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
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// BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
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// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
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// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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// ***************************************************************************
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// ***************************************************************************
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`timescale 1ns/100ps
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module ad9671_fmc_spi (
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spi_ad9671_csn,
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spi_ad9516_csn,
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spi_ad9553_csn,
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spi_clk,
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spi_mosi,
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spi_miso,
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spi_ad9671_sdio,
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spi_ad9516_sdio,
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spi_ad9553_sdio);
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// 4 wire
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input spi_ad9671_csn;
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input spi_ad9516_csn;
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input spi_ad9553_csn;
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input spi_clk;
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input spi_mosi;
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output spi_miso;
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// 3 wire
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inout spi_ad9671_sdio;
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inout spi_ad9516_sdio;
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input spi_ad9553_sdio;
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// internal registers
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reg [ 5:0] spi_count = 'd0;
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reg spi_rd_wr_n = 'd0;
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reg spi_enable = 'd0;
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// internal signals
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wire spi_csn_s;
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wire spi_enable_s;
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wire spi_ad9516_miso_s;
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wire spi_ad9671_miso_s;
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wire spi_ad9553_miso_s;
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// check on rising edge and change on falling edge
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assign spi_csn_s = spi_ad9553_csn & spi_ad9516_csn & spi_ad9671_csn;
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assign spi_enable_s = spi_enable & ~spi_csn_s;
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always @(posedge spi_clk or posedge spi_csn_s) begin
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if (spi_csn_s == 1'b1) begin
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spi_count <= 6'd0;
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spi_rd_wr_n <= 1'd0;
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end else begin
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spi_count <= spi_count + 1'b1;
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if (spi_count == 6'd0) begin
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spi_rd_wr_n <= spi_mosi;
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end
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end
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end
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always @(negedge spi_clk or posedge spi_csn_s) begin
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if (spi_csn_s == 1'b1) begin
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spi_enable <= 1'b0;
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end else begin
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if (((spi_count == 6'd16) && (spi_ad9671_csn == 1'b0)) ||
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((spi_count == 6'd16) && (spi_ad9516_csn == 1'b0)) ||
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((spi_count == 6'd16) && (spi_ad9553_csn == 1'b0))) begin
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spi_enable <= spi_rd_wr_n;
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end
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end
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end
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assign spi_miso = ((spi_ad9671_miso_s & ~spi_ad9671_csn) |
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(spi_ad9516_miso_s & ~spi_ad9516_csn) |
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(spi_ad9553_miso_s & ~spi_ad9553_csn));
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// io buffers
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IOBUF i_iobuf_ad9671_sdio (
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.T (spi_enable_s),
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.I (spi_mosi),
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.O (spi_ad9671_miso_s),
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.IO (spi_ad9671_sdio));
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IOBUF i_iobuf_ad9516_sdio (
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.T (spi_enable_s),
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.I (spi_mosi),
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.O (spi_ad9516_miso_s),
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.IO (spi_ad9516_sdio));
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IOBUF i_iobuf_clk_sdio (
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.T (spi_enable_s),
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.I (spi_mosi),
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.O (spi_ad9553_miso_s),
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.IO (spi_ad9553_sdio));
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endmodule
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// ***************************************************************************
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// ***************************************************************************
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