uint16_t rx_bd_tail; /**< Index of last rx bd. */
uint16_t rx_cq_head; /**< Index of current rcq bd. */
uint16_t rx_cq_tail; /**< Index of last rcq bd. */
uint16_t rx_bd_tail; /**< Index of last rx bd. */
uint16_t rx_cq_head; /**< Index of current rcq bd. */
uint16_t rx_cq_tail; /**< Index of last rcq bd. */