| Bit15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 |
| FNCERR | FNUM[10:5] | ||||||
| AccessR | R | R | R | R | R | R | |
| Reset0 | 0 | 0 | 0 | 0 | 0 | 0 | |
| Bit7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
| FNUM[4:0] | MFNUM[2:0] | ||||||
| AccessR | R | R | R | R | R | R | R |
| Reset0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
Frame Number CRC Error
This bit is cleared upon receiving a USB reset.
This bit is set when a corrupted frame number (or micro-frame number) is received.
This bit and the SOF (or MSOF) interrupt bit are updated at the same time.
Frame Number
These bits are cleared upon receiving a USB reset.
These bits are updated with the frame number information as provided from the last SOF packet even if a corrupted SOF is received.
Micro Frame Number
These bits are cleared upon receiving a USB reset or at the beginning of each Start-of-Frame (SOF interrupt).
These bits are updated with the micro-frame number information as provided from the last MSOF packet even if a corrupted MSOF is received.