FIFO Data Count Register
| R | Receive FIFO Data Count Indicate the quantity of receive data stored in FRDRH and FRDRL (Valid only in asynchronous mode(including multi-processor) or clock synchronous mode, while FCR.FM=1) |
| Reserved | These bits are read as 000. |
| T | Transmit FIFO Data Count Indicate the quantity of non-transmit data stored in FTDRH and FTDRL (Valid only in asynchronous mode(including multi-processor) or clock synchronous mode, while FCR.FM=1) |
| Reserved | These bits are read as 000. |