module Computer_System_mm_interconnect_1_router
(
    // -------------------
    // Clock & Reset
    // -------------------
    input clk,
    input reset,

    // -------------------
    // Command Sink (Input)
    // -------------------
    input                       sink_valid,
    input  [129-1 : 0]    sink_data,
    input                       sink_startofpacket,
    input                       sink_endofpacket,
    output                      sink_ready,

    // -------------------
    // Command Source (Output)
    // -------------------
    output                          src_valid,
    output reg [129-1    : 0] src_data,
    output reg [9-1 : 0] src_channel,
    output                          src_startofpacket,
    output                          src_endofpacket,
    input                           src_ready
);

    // -------------------------------------------------------
    // Local parameters and variables
    // -------------------------------------------------------
    localparam PKT_ADDR_H = 67;
    localparam PKT_ADDR_L = 36;
    localparam PKT_DEST_ID_H = 104;
    localparam PKT_DEST_ID_L = 101;
    localparam PKT_PROTECTION_H = 119;
    localparam PKT_PROTECTION_L = 117;
    localparam ST_DATA_W = 129;
    localparam ST_CHANNEL_W = 9;
    localparam DECODER_TYPE = 0;

    localparam PKT_TRANS_WRITE = 70;
    localparam PKT_TRANS_READ  = 71;

    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'h10 - 64'h0); 
    localparam PAD1 = log2ceil(64'h50 - 64'h40); 
    localparam PAD2 = log2ceil(64'h60 - 64'h50); 
    localparam PAD3 = log2ceil(64'h2048 - 64'h2040); 
    localparam PAD4 = log2ceil(64'h3030 - 64'h3020); 
    localparam PAD5 = log2ceil(64'h3040 - 64'h3030); 
    localparam PAD6 = log2ceil(64'h3070 - 64'h3060); 
    localparam PAD7 = log2ceil(64'h3080 - 64'h3070); 
    localparam PAD8 = log2ceil(64'h80000 - 64'h40000); 
    // -------------------------------------------------------
    // 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'h80000;
    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;
    localparam REAL_ADDRESS_RANGE = OPTIMIZED_ADDR_H - PKT_ADDR_L;

      reg [PKT_ADDR_W-1 : 0] address;
      always @* begin
        address = {PKT_ADDR_W{1'b0}};
        address [REAL_ADDRESS_RANGE:0] = sink_data[OPTIMIZED_ADDR_H : PKT_ADDR_L];
      end   

    // -------------------------------------------------------
    // 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 [9-1 : 0] default_src_channel;




    // -------------------------------------------------------
    // Write and read transaction signals
    // -------------------------------------------------------
    wire read_transaction;
    assign read_transaction  = sink_data[PKT_TRANS_READ];


    Computer_System_mm_interconnect_1_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
        // --------------------------------------------------

    // ( 0x0 .. 0x10 )
    if ( {address[RG:PAD0],{PAD0{1'b0}}} == 19'h0   ) begin
            src_channel = 9'b000001000;
            src_data[PKT_DEST_ID_H:PKT_DEST_ID_L] = 0;
    end

    // ( 0x40 .. 0x50 )
    if ( {address[RG:PAD1],{PAD1{1'b0}}} == 19'h40  && read_transaction  ) begin
            src_channel = 9'b000010000;
            src_data[PKT_DEST_ID_H:PKT_DEST_ID_L] = 3;
    end

    // ( 0x50 .. 0x60 )
    if ( {address[RG:PAD2],{PAD2{1'b0}}} == 19'h50   ) begin
            src_channel = 9'b000100000;
            src_data[PKT_DEST_ID_H:PKT_DEST_ID_L] = 2;
    end

    // ( 0x2040 .. 0x2048 )
    if ( {address[RG:PAD3],{PAD3{1'b0}}} == 19'h2040  && read_transaction  ) begin
            src_channel = 9'b000000010;
            src_data[PKT_DEST_ID_H:PKT_DEST_ID_L] = 4;
    end

    // ( 0x3020 .. 0x3030 )
    if ( {address[RG:PAD4],{PAD4{1'b0}}} == 19'h3020   ) begin
            src_channel = 9'b001000000;
            src_data[PKT_DEST_ID_H:PKT_DEST_ID_L] = 1;
    end

    // ( 0x3030 .. 0x3040 )
    if ( {address[RG:PAD5],{PAD5{1'b0}}} == 19'h3030   ) begin
            src_channel = 9'b000000001;
            src_data[PKT_DEST_ID_H:PKT_DEST_ID_L] = 5;
    end

    // ( 0x3060 .. 0x3070 )
    if ( {address[RG:PAD6],{PAD6{1'b0}}} == 19'h3060   ) begin
            src_channel = 9'b010000000;
            src_data[PKT_DEST_ID_H:PKT_DEST_ID_L] = 6;
    end

    // ( 0x3070 .. 0x3080 )
    if ( {address[RG:PAD7],{PAD7{1'b0}}} == 19'h3070   ) begin
            src_channel = 9'b000000100;
            src_data[PKT_DEST_ID_H:PKT_DEST_ID_L] = 7;
    end

    // ( 0x40000 .. 0x80000 )
    if ( {address[RG:PAD8],{PAD8{1'b0}}} == 19'h40000   ) begin
            src_channel = 9'b100000000;
            src_data[PKT_DEST_ID_H:PKT_DEST_ID_L] = 8;
    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