module cpu_sys_addr_router
(
    // -------------------
    // Clock & Reset
    // -------------------
    input clk,
    input reset,

    // -------------------
    // Command Sink (Input)
    // -------------------
    input                       sink_valid,
    input  [90-1 : 0]    sink_data,
    input                       sink_startofpacket,
    input                       sink_endofpacket,
    output                      sink_ready,

    // -------------------
    // Command Source (Output)
    // -------------------
    output                          src_valid,
    output reg [90-1    : 0] src_data,
    output reg [5-1 : 0] src_channel,
    output                          src_startofpacket,
    output                          src_endofpacket,
    input                           src_ready
);

    // -------------------------------------------------------
    // Local parameters and variables
    // -------------------------------------------------------
    localparam PKT_ADDR_H = 52;
    localparam PKT_ADDR_L = 36;
    localparam PKT_DEST_ID_H = 79;
    localparam PKT_DEST_ID_L = 77;
    localparam PKT_PROTECTION_H = 83;
    localparam PKT_PROTECTION_L = 81;
    localparam ST_DATA_W = 90;
    localparam ST_CHANNEL_W = 5;
    localparam DECODER_TYPE = 0;

    localparam PKT_TRANS_WRITE = 55;
    localparam PKT_TRANS_READ  = 56;

    localparam PKT_ADDR_W = PKT_ADDR_H-PKT_ADDR_L + 1;
    localparam PKT_DEST_ID_W = PKT_DEST_ID_H-PKT_DEST_ID_L + 1;



    // -------------------------------------------------------
    // Figure out the number of bits to mask off for each slave span
    // during address decoding
    // -------------------------------------------------------
    localparam PAD0 = log2ceil(64'h10000 - 64'h8000); 
    localparam PAD1 = log2ceil(64'h11000 - 64'h10800); 
    localparam PAD2 = log2ceil(64'h11020 - 64'h11000); 
    localparam PAD3 = log2ceil(64'h11030 - 64'h11020); 
    localparam PAD4 = log2ceil(64'h11038 - 64'h11030); 
    // -------------------------------------------------------
    // Work out which address bits are significant based on the
    // address range of the slaves. If the required width is too
    // large or too small, we use the address field width instead.
    // -------------------------------------------------------
    localparam ADDR_RANGE = 64'h11038;
    localparam RANGE_ADDR_WIDTH = log2ceil(ADDR_RANGE);
    localparam OPTIMIZED_ADDR_H = (RANGE_ADDR_WIDTH > PKT_ADDR_W) ||
                                  (RANGE_ADDR_WIDTH == 0) ?
                                        PKT_ADDR_H :
                                        PKT_ADDR_L + RANGE_ADDR_WIDTH - 1;

    localparam RG = RANGE_ADDR_WIDTH-1;

      wire [PKT_ADDR_W-1 : 0] address = sink_data[OPTIMIZED_ADDR_H : PKT_ADDR_L];

    // -------------------------------------------------------
    // Pass almost everything through, untouched
    // -------------------------------------------------------
    assign sink_ready        = src_ready;
    assign src_valid         = sink_valid;
    assign src_startofpacket = sink_startofpacket;
    assign src_endofpacket   = sink_endofpacket;

    wire [PKT_DEST_ID_W-1:0] default_destid;
    wire [5-1 : 0] default_src_channel;





    cpu_sys_addr_router_default_decode the_default_decode(
      .default_destination_id (default_destid),
      .default_wr_channel   (),
      .default_rd_channel   (),
      .default_src_channel  (default_src_channel)
    );

    always @* begin
        src_data    = sink_data;
        src_channel = default_src_channel;
        src_data[PKT_DEST_ID_H:PKT_DEST_ID_L] = default_destid;

        // --------------------------------------------------
        // Address Decoder
        // Sets the channel and destination ID based on the address
        // --------------------------------------------------

    // ( 0x8000 .. 0x10000 )
    if ( {address[RG:PAD0],{PAD0{1'b0}}} == 17'h8000   ) begin
            src_channel = 5'b00100;
            src_data[PKT_DEST_ID_H:PKT_DEST_ID_L] = 1;
    end

    // ( 0x10800 .. 0x11000 )
    if ( {address[RG:PAD1],{PAD1{1'b0}}} == 17'h10800   ) begin
            src_channel = 5'b00001;
            src_data[PKT_DEST_ID_H:PKT_DEST_ID_L] = 3;
    end

    // ( 0x11000 .. 0x11020 )
    if ( {address[RG:PAD2],{PAD2{1'b0}}} == 17'h11000   ) begin
            src_channel = 5'b01000;
            src_data[PKT_DEST_ID_H:PKT_DEST_ID_L] = 4;
    end

    // ( 0x11020 .. 0x11030 )
    if ( {address[RG:PAD3],{PAD3{1'b0}}} == 17'h11020   ) begin
            src_channel = 5'b00010;
            src_data[PKT_DEST_ID_H:PKT_DEST_ID_L] = 0;
    end

    // ( 0x11030 .. 0x11038 )
    if ( {address[RG:PAD4],{PAD4{1'b0}}} == 17'h11030   ) begin
            src_channel = 5'b10000;
            src_data[PKT_DEST_ID_H:PKT_DEST_ID_L] = 2;
    end

end


    // --------------------------------------------------
    // Ceil(log2()) function
    // --------------------------------------------------
    function integer log2ceil;
        input reg[65:0] val;
        reg [65:0] i;

        begin
            i = 1;
            log2ceil = 0;

            while (i < val) begin
                log2ceil = log2ceil + 1;
                i = i << 1;
            end
        end
    endfunction

endmodule