Datasheet

284
ATmega16U4/32U4 [DATASHEET]
Atmel-7766J-USB-ATmega16U4/32U4-Datasheet_04/2016
• Bit 7 - ADDEN - Address Enable Bit
Set to activate the UADD (USB address).
Cleared by hardware. Clearing by software has no effect.
See “Address Setup” on page 272 for more details.
• Bits 6-0 - UADD6:0 - USB Address Bits
Load by software to configure the device address
• 7-3 - Reserved
The value read from these bits is always 0. Do not set these bits.
• 2-0 - FNUM10:8 - Frame Number Upper Value
Set by hardware. These bits are the three MSB of the 11-bits Frame Number information. They are provided in
the last received SOF packet. FNUM is updated if a corrupted SOF is received.
• Bits 7:0 - FNUM7:0 - Frame Number Lower Value
Set by hardware. These bits are the 8 LSB of the 11-bits Frame Number information
Bit 76543210
ADDEN UADD6:0 UDADDR
Read/Write W R/W R/W R/W R/W R/W R/W R/W
Initial Value00000000
Bit 76543 2 1 0
- - - - - FNUM10:8 UDFNUMH
Read/WriteRRRRR R R R
Initial Value 0 0 0 0 0 0 0 0
Bit 76543210
FNUM7:0 UDFNUML
Read/WriteRRRRRRRR
Initial Value 0 0 0 0 0 0 0 0