check_response(ins: instruction_s) is only {
            // Check for overflow
            if (ins.din2 > ins.din1) {
                // Underflow occurs
                check that ins.resp == 2 else
                    dut_error(appendf("[R==>Port %s invalid response.<==R]\n \
                                Instruction %s %u %u,\n \
                                expected resp: %d \n \
                                recieved resp: %d \n ",
                                ins.port, ins.cmd_in, ins.din1, ins.din2, 2, ins.resp));
            } else {
                // Check correct subtraction occurs
                check that ins.resp == 01;
                check that (ins.dout == (ins.din1 - ins.din2)) else
                    dut_error(appendf("[R==>Port %s invalid output.<==R]\n \
                                Instruction %s %u %u,\n \
                                expected %032.32b \t %u,\n \
                                received %032.32b \t %u.\n",
                                ins.port, ins.cmd_in, ins.din1, ins.din2,
                                (ins.din1 - ins.din2),
                                (ins.din1 - ins.din2),
                                ins.dout,ins.dout));
            };
        };