Receive FIFO status of Rx channel 0
| INFIFO_FULL_L1 | L1 Rx FIFO full signal for Rx channel 0. |
| INFIFO_EMPTY_L1 | L1 Rx FIFO empty signal for Rx channel 0. |
| INFIFO_FULL_L2 | L2 Rx FIFO full signal for Rx channel 0. |
| INFIFO_EMPTY_L2 | L2 Rx FIFO empty signal for Rx channel 0. |
| INFIFO_FULL_L3 | L3 Rx FIFO full signal for Rx channel 0. |
| INFIFO_EMPTY_L3 | L3 Rx FIFO empty signal for Rx channel 0. |
| INFIFO_CNT_L1 | The register stores the byte number of the data in L1 Rx FIFO for Rx channel 0. |
| INFIFO_CNT_L2 | The register stores the byte number of the data in L2 Rx FIFO for Rx channel 0. |
| INFIFO_CNT_L3 | The register stores the byte number of the data in L3 Rx FIFO for Rx channel 0. |
| IN_REMAIN_UNDER_1B_L3 | reserved |
| IN_REMAIN_UNDER_2B_L3 | reserved |
| IN_REMAIN_UNDER_3B_L3 | reserved |
| IN_REMAIN_UNDER_4B_L3 | reserved |
| IN_BUF_HUNGRY | reserved |