RX_THD_LVL=NOT_EMPTY, TX_THD_LVL=EMPTY
Target FIFO Control Register.
| TX_FLUSH | Flush TX FIFO. |
| RX_FLUSH | Flush RX FIFO. |
| UNLOCK | Unlock FIFO Triggers. |
| TX_THD_LVL | TX FIFO trigger level. 0 (EMPTY): Trigger when empty. 1 (QUARTER_FULL): Trigger when quarter full or less. 2 (HALF_FULL): Trigger when half full or less. 3 (ALMOST_FULL): Trigger when almost full or less. |
| RX_THD_LVL | RX FIFO trigger level. 0 (NOT_EMPTY): Trigger when empty. 1 (QUARTER_FULL): Trigger when quarter full or less. 2 (HALF_FULL): Trigger when half full or less. 3 (3_QUARTER_FULL): Trigger when 3 quarters full or less. |
| TX_LVL | Number of messages in TX FIFO. |
| RX_LVL | Number of messages in RX FIFO. |
| TX_FULL | TX FIFO Full flag. |
| RX_EM | RX FIFO Empty Flag. |