37.8.4 Device Frame Number
| Name: | FNUM |
| Offset: | 0x10 |
| Reset: | 0x0000 |
| Property: | Read only |
| Bit | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | |
| FNCERR | FNUM[10:5] | ||||||||
| Access | R/W | R/W | R/W | R/W | R/W | R/W | R/W | ||
| Reset | 0 | 0 | 0 | 0 | 0 | 0 | 0 | ||
| Bit | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | |
| FNUM[4:0] | MFNUM[2:0] | ||||||||
| Access | R/W | R/W | R/W | R/W | R/W | R/W | R/W | R/W | |
| Reset | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |
Bit 15 – FNCERR 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.
Bits 13:3 – FNUM[10:0] 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.
Bits 2:0 – MFNUM[2:0] 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.