Currently type parameter override is not supported for this datatype.

It seemed that cadence's tool do not support transfer type:mailbox, array, queue through config_db(unfortunately tlm port, export, ap, is based on mailbox, which cannot be pass). But mentor's tool can work properly.

In IEEE std. 1800-2009, this situation is not mentioned.

If you want support for tool problems, please use the correct procedure at our support site  as we cannot do much in a public forum to analyse your problems.

Luckily for you the solution to your issue is quite easy: create a wrapper class around the mailbox, since you can use classes with the config DB.

Try to wrap your mailbox in a class and pass that. This might work. Here's some code (not tested):

class mailbox_wrapper;

  usbpd_prot_pkt_mailbox_t mbox;

endclass

mbox_wrapper wrapper = new();

wrapper.mbox = dut_prot2pe_mbx[0];

uvm_config_db #(mailbox_wrapper) :: set(null, "*","dut_prot2pe_mbx_0" , wrapper);

You'll also have to update your get to handle the wrapper class instead of a native mailbox.

Here's an example. This hasn't been tested but should be complete.

package mbox_pkg;
import uvm_pkg::*;
class mbox_wrap #(type T=uvm_object);
  mailbox #(T) mbox;
  function new (int bound=0);
    mbox=new(bound);
  endfunction
  function int num();
    return mbox.num();
  endfunction
  task put (input T message);
    mbox.put(message);
  endtask
  function int try_put (input T message);
    return mbox.try_put(message);
  endfunction
  task get (ref T message);
    mbox.get(message);
  endtask
  function int try_get (ref T message);
    return mbox.try_get(message);
  endfunction
  task peek (ref T message);
    mbox.peek(message);
  endtask
  function int try_peek (ref T message);
    return mbox.try_peek(message);
  endfunction
endclass

endpackage