Mine

        {
                ROBO_ARL_SEARCH_CTRL_STRUC ctl;
                ROBO_ARL_SEARCH_RESULT_STRUC ret;

                ctl.ARLStart=1;

                robo_write16(&robo, ROBO_ARLIO_PAGE, ROBO_ARL_SEARCH_CTRL, *(u8 *)&ctl);

                while (1) {
                        u16 addr = robo_read16(&robo, ROBO_ARLIO_PAGE, ROBO_ARL_SEARCH_ADDR);

                        robo_read(&robo, ROBO_ARLIO_PAGE, ROBO_ARL_SEARCH_RESULT, (u16 *)&ret, 4);

                        if (!ret.ctrl.valid) break;

                        printf("%04x> ",addr);

                        printf("mac: %02x:%02x:%02x:%02x:%02x:%02x ",
                                ret.mac.macBytes[5],
                                ret.mac.macBytes[4],
                                ret.mac.macBytes[3],
                                ret.mac.macBytes[2],
                                ret.mac.macBytes[1],
                                ret.mac.macBytes[0]);

                        printf("port: %02x vid: %02x age: %02x valid: %02x\n",
                                ret.ctrl.portID,
                                ret.ctrl.vid,
                                ret.ctrl.age,
                                ret.ctrl.valid);
                        }
        }