pluto_hdl_adi/projects/fmcjesdadc1/common/fmcjesdadc1_spi.v

151 lines
5.4 KiB
Verilog

// ***************************************************************************
// ***************************************************************************
// Copyright 2011(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.
// ***************************************************************************
// ***************************************************************************
// ***************************************************************************
// ***************************************************************************
`timescale 1ns/100ps
module fmcjesdadc1_spi (
// master clock
sys_clk,
// 4-wire spi interface
spi4_csn,
spi4_clk,
spi4_mosi,
spi4_miso,
// 3-wire spi interface
spi3_csn,
spi3_clk,
spi3_sdio);
// parameters
localparam FMC27X_CPLD = 8'h00;
localparam FMC27X_AD9517 = 8'h84;
localparam FMC27X_AD9250_0 = 8'h80;
localparam FMC27X_AD9250_1 = 8'h81;
localparam FMC27X_AD9129_0 = 8'h82;
localparam FMC27X_AD9129_1 = 8'h83;
// master clock
input sys_clk;
// 4-wire spi interface
input spi4_csn;
input spi4_clk;
input spi4_mosi;
output spi4_miso;
// 3-wire spi interface
output spi3_csn;
output spi3_clk;
inout spi3_sdio;
// internal registers
reg spi4_clk_d = 'd0;
reg spi4_csn_d = 'd0;
reg [ 5:0] spi4_clkcnt = 'd0;
reg [ 6:0] spi4_bitcnt = 'd0;
reg [ 7:0] spi4_devid = 'd0;
reg spi4_rwn = 'd0;
reg spi3_enable = 'd0;
// pass through most of the stuff (no need to change clock or miso or mosi)
assign spi4_miso = spi3_sdio;
assign spi3_csn = spi4_csn;
assign spi3_clk = spi4_clk;
assign spi3_sdio = ((spi4_csn == 1'b0) && (spi3_enable == 1'b1)) ? 1'bz : spi4_mosi;
// the spi4 format is a preamble that selects a particular device, so all we need
// to do is collect the first 8 bits, then control the tristate based on the
// device's address and data widths. the details of the spi formats can be found
// in the data sheet of the devices.
always @(posedge sys_clk) begin
spi4_clk_d <= spi4_clk;
spi4_csn_d <= spi4_csn;
if ((spi4_clk == 1'b1) && (spi4_clk_d == 1'b0)) begin
spi4_clkcnt <= 6'd0;
end else begin
spi4_clkcnt <= spi4_clkcnt + 1'b1;
end
if ((spi4_csn == 1'b1) && (spi4_csn_d == 1'b0)) begin
spi4_bitcnt <= 7'd0;
spi4_devid <= 8'd0;
spi4_rwn <= 1'd0;
end else if ((spi4_clk == 1'b1) && (spi4_clk_d == 1'b0)) begin
spi4_bitcnt <= spi4_bitcnt + 1'b1;
if (spi4_bitcnt < 8) begin
spi4_devid <= {spi4_devid[6:0], spi4_mosi};
end
if (spi4_bitcnt == 8) begin
spi4_rwn <= spi4_mosi;
end
end
if (spi4_csn == 1'b0) begin
if ((spi4_devid == FMC27X_CPLD) || (spi4_devid == FMC27X_AD9129_0) ||
(spi4_devid == FMC27X_AD9129_1)) begin
if ((spi4_bitcnt == 16) && (spi4_clkcnt == 8)) begin
spi3_enable <= spi4_rwn;
end
end else if ((spi4_devid == FMC27X_AD9517) || (spi4_devid == FMC27X_AD9250_0) ||
(spi4_devid == FMC27X_AD9250_1)) begin
if ((spi4_bitcnt == 24) && (spi4_clkcnt == 8)) begin
spi3_enable <= spi4_rwn;
end
end
end else begin
spi3_enable <= 1'b0;
end
end
endmodule
// ***************************************************************************
// ***************************************************************************