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//
// Copyright 2011 Ettus Research LLC
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program 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. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
//
module s3a_icap_wb
(input clk, input reset,
input cyc_i, input stb_i, input we_i, output ack_o,
input [31:0] dat_i, output [31:0] dat_o);//, output [31:0] debug_out);
assign dat_o[31:8] = 24'd0;
wire BUSY, CE, WRITE, ICAPCLK;
//changed this to gray-ish code to prevent glitching
reg [2:0] icap_state;
localparam ICAP_IDLE = 0;
localparam ICAP_WR0 = 1;
localparam ICAP_WR1 = 5;
localparam ICAP_RD0 = 2;
localparam ICAP_RD1 = 3;
always @(posedge clk)
if(reset)
icap_state <= ICAP_IDLE;
else
case(icap_state)
ICAP_IDLE :
begin
if(stb_i & cyc_i)
if(we_i)
icap_state <= ICAP_WR0;
else
icap_state <= ICAP_RD0;
end
ICAP_WR0 :
icap_state <= ICAP_WR1;
ICAP_WR1 :
icap_state <= ICAP_IDLE;
ICAP_RD0 :
icap_state <= ICAP_RD1;
ICAP_RD1 :
icap_state <= ICAP_IDLE;
endcase // case (icap_state)
assign WRITE = (icap_state == ICAP_WR0) | (icap_state == ICAP_WR1);
assign CE = (icap_state == ICAP_WR0) | (icap_state == ICAP_RD0);
assign ICAPCLK = CE & (~clk);
assign ack_o = (icap_state == ICAP_WR1) | (icap_state == ICAP_RD1);
//assign debug_out = {17'd0, BUSY, dat_i[7:0], ~CE, ICAPCLK, ~WRITE, icap_state};
ICAP_SPARTAN3A ICAP_SPARTAN3A_inst
(.BUSY(BUSY), // Busy output
.O(dat_o[7:0]), // 32-bit data output
.CE(~CE), // Clock enable input
.CLK(ICAPCLK), // Clock input
.I(dat_i[7:0]), // 32-bit data input
.WRITE(~WRITE) // Write input
);
endmodule // s3a_icap_wb
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