pluto_hdl_adi/library/axi_gpreg/axi_gpreg_io.v

145 lines
4.5 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 axi_gpreg_io (
// gpio
up_gp_ioenb,
up_gp_out,
up_gp_in,
// bus interface
up_rstn,
up_clk,
up_wreq,
up_waddr,
up_wdata,
up_wack,
up_rreq,
up_raddr,
up_rdata,
up_rack);
// parameters
parameter ID = 0;
// gpio
output [31:0] up_gp_ioenb;
output [31:0] up_gp_out;
input [31:0] up_gp_in;
// bus interface
input up_rstn;
input up_clk;
input up_wreq;
input [13:0] up_waddr;
input [31:0] up_wdata;
output up_wack;
input up_rreq;
input [13:0] up_raddr;
output [31:0] up_rdata;
output up_rack;
// internal registers
reg up_wack = 'd0;
reg [31:0] up_gp_ioenb = 'd0;
reg [31:0] up_gp_out = 'd0;
reg up_rack = 'd0;
reg [31:0] up_rdata = 'd0;
// internal signals
wire up_wreq_s;
wire up_rreq_s;
// decode block select
assign up_wreq_s = (up_waddr[13:4] == ID) ? up_wreq : 1'b0;
assign up_rreq_s = (up_raddr[13:4] == ID) ? up_rreq : 1'b0;
// processor write interface
always @(negedge up_rstn or posedge up_clk) begin
if (up_rstn == 0) begin
up_wack <= 'd0;
up_gp_ioenb <= {32{1'b1}};
up_gp_out <= 'd0;
end else begin
up_wack <= up_wreq_s;
if ((up_wreq_s == 1'b1) && (up_waddr[3:0] == 4'h0)) begin
up_gp_ioenb <= up_wdata;
end
if ((up_wreq_s == 1'b1) && (up_waddr[3:0] == 4'h1)) begin
up_gp_out <= up_wdata;
end
end
end
// processor read interface
always @(negedge up_rstn or posedge up_clk) begin
if (up_rstn == 0) begin
up_rack <= 'd0;
up_rdata <= 'd0;
end else begin
up_rack <= up_rreq_s;
if (up_rreq_s == 1'b1) begin
case (up_raddr[3:0])
4'b0000: up_rdata <= up_gp_ioenb;
4'b0001: up_rdata <= up_gp_out;
4'b0010: up_rdata <= up_gp_in;
default: up_rdata <= 32'd0;
endcase
end else begin
up_rdata <= 32'd0;
end
end
end
endmodule
// ***************************************************************************
// ***************************************************************************