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[raggedstone] / heartbeat / source / pcidec.v

//  Copyright (C) 2005 Peio Azkarate, peio@opencores.org
//  Copyright (C) 2006 Jeff Carr, jcarr@opencores.org
//      Copyleft GPL v2

module pcidec_new (clk_i, nrst_i, ad_i, cbe_i, idsel_i, bar0_i, memEN_i,
        pciadrLD_i, adrcfg_o, adrmem_o, adr_o, cmd_o);

        // General 
        input clk_i;
        input nrst_i;
        // pci 
        input [31:0] ad_i;
        input [3:0] cbe_i;
        input idsel_i;
        // control
        input [31:25] bar0_i;
        input memEN_i;
        input pciadrLD_i;
        output adrcfg_o;
        output adrmem_o;
        output [24:1] adr_o;
        output [3:0] cmd_o;

        reg [31:0] adr;
        reg [3:0] cmd;
        reg idsel_s;
        wire a1;

        //+-------------------------------------------------------------------------+
        //|  Load PCI Signals                                                                                                           |
        //+-------------------------------------------------------------------------+

        always @( negedge nrst_i or posedge clk_i )
        begin
                if( nrst_i == 0 )
                begin
                        adr <= 23'b1111_1111_1111_1111_1111_111;
                        cmd <= 3'b111;
                        idsel_s <= 1'b0;
                end
                else
                        if ( pciadrLD_i == 1 )
                        begin
                                adr <= ad_i;
                                cmd <= cbe_i;
                                idsel_s <= idsel_i;
                        end
        end

        assign adrmem_o = (
                ( memEN_i == 1'b1 ) &&
                ( adr [31:25] == bar0_i ) &&
                ( adr [1:0] == 2'b00 ) &&
                ( cmd [3:1] == 3'b011 )
        ) ? 1'b1 : 1'b0;

        assign adrcfg_o = (
                ( idsel_s == 1'b1 ) &&
                ( adr [1:0] == 2'b00 ) &&
                ( cmd [3:1] == 3'b101 )
        ) ? 1'b1 : 1'b0;

        assign a1 = ~ ( cbe_i [3] && cbe_i [2] );
        assign adr_o = {adr [24:2], a1};
        assign cmd_o = cmd;

endmodule