pluto_hdl_adi/library/common/up_xfer_cntrl.v

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// ***************************************************************************
// ***************************************************************************
// 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 up_xfer_cntrl #(
parameter DATA_WIDTH = 8
) (
// up interface
input up_rstn,
input up_clk,
input [(DATA_WIDTH-1):0] up_data_cntrl,
output up_xfer_done,
// device interface
input d_rst,
input d_clk,
output [(DATA_WIDTH-1):0] d_data_cntrl
);
// internal registers
reg up_xfer_state_m1 = 'd0;
reg up_xfer_state_m2 = 'd0;
reg up_xfer_state = 'd0;
reg [ 5:0] up_xfer_count = 'd0;
reg up_xfer_done_int = 'd0;
reg up_xfer_toggle = 'd0;
reg [(DATA_WIDTH-1):0] up_xfer_data = 'd0;
reg d_xfer_toggle_m1 = 'd0;
reg d_xfer_toggle_m2 = 'd0;
reg d_xfer_toggle_m3 = 'd0;
reg d_xfer_toggle = 'd0;
reg [(DATA_WIDTH-1):0] d_data_cntrl_int = 'd0;
// internal signals
wire up_xfer_enable_s;
wire d_xfer_toggle_s;
// device control transfer
assign up_xfer_done = up_xfer_done_int;
assign up_xfer_enable_s = up_xfer_state ^ up_xfer_toggle;
always @(posedge up_clk) begin
if (up_rstn == 1'b0) begin
up_xfer_state_m1 <= 'd0;
up_xfer_state_m2 <= 'd0;
up_xfer_state <= 'd0;
up_xfer_count <= 'd0;
up_xfer_done_int <= 'd0;
up_xfer_toggle <= 'd0;
up_xfer_data <= 'd0;
end else begin
up_xfer_state_m1 <= d_xfer_toggle;
up_xfer_state_m2 <= up_xfer_state_m1;
up_xfer_state <= up_xfer_state_m2;
up_xfer_count <= up_xfer_count + 1'd1;
up_xfer_done_int <= (up_xfer_count == 6'd0) ? ~up_xfer_enable_s : 1'b0;
if ((up_xfer_count == 6'd1) && (up_xfer_enable_s == 1'b0)) begin
up_xfer_toggle <= ~up_xfer_toggle;
up_xfer_data <= up_data_cntrl;
end
end
end
assign d_data_cntrl = d_data_cntrl_int;
assign d_xfer_toggle_s = d_xfer_toggle_m3 ^ d_xfer_toggle_m2;
always @(posedge d_clk or posedge d_rst) begin
if (d_rst == 1'b1) begin
d_xfer_toggle_m1 <= 'd0;
d_xfer_toggle_m2 <= 'd0;
d_xfer_toggle_m3 <= 'd0;
d_xfer_toggle <= 'd0;
d_data_cntrl_int <= 'd0;
end else begin
d_xfer_toggle_m1 <= up_xfer_toggle;
d_xfer_toggle_m2 <= d_xfer_toggle_m1;
d_xfer_toggle_m3 <= d_xfer_toggle_m2;
d_xfer_toggle <= d_xfer_toggle_m3;
if (d_xfer_toggle_s == 1'b1) begin
d_data_cntrl_int <= up_xfer_data;
end
end
end
endmodule