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// ============================================================================

//  INW.v

//  - Fetch data from IO.

//

//

//  2009,2010,2012  Robert Finch

//  robfinch@opencores.org

//  Stratford

//

//  

// This source file is free software: you can redistribute it and/or modify 

// it under the terms of the GNU Lesser General Public License as published 

// by the Free Software Foundation, either version 3 of the License, or     

// (at your option) any later version.                                      

//                                                                          

// This source file 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/>.    

//

//

//

//  Verilog 

//

// ============================================================================

//

INW:

        begin

                `INITIATE_CODE_READ

                state <= INW1;

        end

INW1:

        if (ack_i) begin

                `TERMINATE_CODE_READ

                ea <= {12'h000,dat_i};

                state <= INW2;

        end

INW2:

        begin

                cyc_type <= `CT_RDIO;

                mio_o <= 1'b0;

                cyc_o <= 1'b1;

                stb_o <= 1'b1;

                we_o  <= 1'b0;

                adr_o <= ea;

                state <= INW3;

        end

INW3:

        if (ack_i) begin

                cyc_type <= `CT_PASSIVE;

                mio_o <= 1'b1;

                stb_o <= 1'b0;

                res[7:0] <= dat_i;

                state <= INW4;

        end

INW4:

        begin

                cyc_type <= `CT_RDIO;

                mio_o <= 1'b0;

                stb_o <= 1'b1;

                adr_o <= ea_inc;

                state <= INW5;

        end

INW5:

        if (ack_i) begin

                cyc_type <= `CT_PASSIVE;

                mio_o <= 1'b1;

                cyc_o <= 1'b0;

                stb_o <= 1'b0;

                we_o  <= 1'b0;

                wrregs <= 1'b1;

                w <= 1'b1;

                rrr <= 3'd0;

                res[15:8] <= dat_i;

                state <= IFETCH;

        end