In reply to saritr:
All shared signals between interfaces should be made a ports of your interface.
interface pakmx_if_in (input logic clk, input logic rst);
logic [7:0] data_in;
logic data_en;
logic packet_start;
logic packet_err;
logic busy;
endinterface
interface pakmx_if_out (input logic clk, input logic rst);
logic ch_data_en;
logic ch_start;
logic [7:0] ch_data;
endinterface
module top;
logic clk, rst;
pakmx_if_in if_in(.*)
pakmx_if_out if_out(.*);
...
endmodule
If one interface is the source of the clk or reset, then change the
input to
output accordingly.