module Computer_System_mm_interconnect_4_router_002
(
    // -------------------
    // Clock & Reset
    // -------------------
    input clk,
    input reset,

    // -------------------
    // Command Sink (Input)
    // -------------------
    input                       sink_valid,
    input  [74-1 : 0]    sink_data,
    input                       sink_startofpacket,
    input                       sink_endofpacket,
    output                      sink_ready,

    // -------------------
    // Command Source (Output)
    // -------------------
    output                          src_valid,
    output reg [74-1    : 0] src_data,
    output reg [2-1 : 0] src_channel,
    output                          src_startofpacket,
    output                          src_endofpacket,
    input                           src_ready
);

    // -------------------------------------------------------
    // Local parameters and variables
    // -------------------------------------------------------
    localparam PKT_ADDR_H = 39;
    localparam PKT_ADDR_L = 36;
    localparam PKT_DEST_ID_H = 60;
    localparam PKT_DEST_ID_L = 60;
    localparam PKT_PROTECTION_H = 64;
    localparam PKT_PROTECTION_L = 62;
    localparam ST_DATA_W = 74;
    localparam ST_CHANNEL_W = 2;
    localparam DECODER_TYPE = 1;

    localparam PKT_TRANS_WRITE = 42;
    localparam PKT_TRANS_READ  = 43;

    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
    // -------------------------------------------------------
    // -------------------------------------------------------
    // 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'h0;
    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;
    localparam REAL_ADDRESS_RANGE = OPTIMIZED_ADDR_H - PKT_ADDR_L;

    reg [PKT_DEST_ID_W-1 : 0] destid;

    // -------------------------------------------------------
    // 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 [2-1 : 0] default_src_channel;




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


    Computer_System_mm_interconnect_4_router_002_default_decode the_default_decode(
      .default_destination_id (),
      .default_wr_channel   (),
      .default_rd_channel   (),
      .default_src_channel  (default_src_channel)
    );

    always @* begin
        src_data    = sink_data;
        src_channel = default_src_channel;

        // --------------------------------------------------
        // DestinationID Decoder
        // Sets the channel based on the destination ID.
        // --------------------------------------------------
        destid      = sink_data[PKT_DEST_ID_H : PKT_DEST_ID_L];



        if (destid == 0  && read_transaction) begin
            src_channel = 2'b01;
        end

        if (destid == 1  && write_transaction) begin
            src_channel = 2'b10;
        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