Datasheet

725
32072H–AVR32–10/2012
AT32UC3A3
27.8.3.8 Host Frame Number Register
Register Name: UHFNUM
Access Type: Read/Write
Offset: 0x0420
Reset Value: 0x00000000
• FLENHIGH: Frame Length
In Full speed mode, this field contains the 8 high-order bits of the 16-bit internal frame counter (at 30MHz, counter length is
30000 to ensure a SOF generation every 1 ms).
In High speed mode, this field contains the 8 high-order bits of the 16-bit internal frame counter (at 30MHz, counter length is
3750 to ensure a SOF generation every 125 us).
• FNUM: Frame Number
This field contains the current SOF number.
This field can be written. In this case, the MFNUM field is reset to zero.
• MFNUM: Micro Frame Number
This field contains the current Micro Frame number (can vary from 0 to 7) updated every 125us.
When operating in full-speed mode, this field is tied to zero.
31 30 29 28 27 26 25 24
--------
23 22 21 20 19 18 17 16
FLENHIGH
15 14 13 12 11 10 9 8
- - FNUM[10:5]
76543210
FNUM[4:0] MFNUM