ATmega8U2/16U2/32U2
28. Register Summary
Address
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Page
(0xFF)
(0xFE)
(0xFD)
(0xFC)
(0xFB)
(0xFA)
(0xF9)
(0xF8)
(0xF7)
(0xF6)
(0xF5)
(0xF4)
(0xF3)
(0xF2)
(0xF1)
(0xF0)
(0xEF)
(0xEE)
(0xED)
(0xEC)
(0xEB)
(0xEA)
(0xE9)
(0xE8)
(0xE7)
(0xE6)
(0xE5)
(0xE4)
(0xE3)
(0xE2)
(0xE1)
(0xE0)
(0xDF)
(0xDE)
(0xDD)
(0xDC)
(0xDB)
(0xDA)
(0xD9)
(0xD8)
(0xD7)
(0xD6)
(0xD5)
(0xD4)
(0xD3)
(0xD2)
(0xD1)
(0xD0)
(0xCF)
(0xCE)
(0xCD)
(0xCC)
(0xCB)
(0xCA)
(0xC9)
(0xC8)
(0xC7)
(0xC6)
(0xC5)
(0xC4)
(0xC3)
(0xC2)
(0xC1)
(0xC0)
(0xBF)
Reserved
Reserved
Reserved
Reserved
UPOE
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
UPWE1
UPWE0
UPDRV1
UPDRV0
SCKI
DATAI
DPI
DMI
page 195
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
UEINT
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
EPINT4:0
-
page 222
Reserved
UEBCLX
UEDATX
UEIENX
-
-
-
-
-
BYCT7:0
DAT7:0
page 221
page 221
page 220
page 218
page 217
page 216
page 215
page 214
page 214
page 214
page 219
FLERRE
NAKINE
-
-
NAKOUTE
RXSTPE
-
RXOUTE
CTRLDIR
STALLEDE
TXINE
UESTA1X
UESTA0X
UECFG1X
UECFG0X
UECONX
UERST
-
-
-
-
CURRBK1:0
NBUSYBK1:0
ALLOC
CFGOK
-
OVERFI
UNDERFI
DTSEQ1:0
EPBK1:0
EPSIZE2:0
-
EPTYPE1:0
-
-
-
-
-
-
EPDIR
EPEN
-
-
STALLRQ
STALLRQC
RSTDT
-
-
-
-
EPRST4:0
UENUM
-
-
-
-
-
EPNUM2:0
UEINTX
FIFOCON
NAKINI
RWAL
NAKOUTI
RXSTPI
RXOUTI
STALLEDI
TXINI
Reserved
UDMFN
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
FNCERR
-
-
page 213
page 213
page 213
page 212
page 211
page 210
page 209
UDFNUMH
UDFNUML
UDADDR
UDIEN
FNUM10:8
FNUM7:0
ADDEN
UADD6:0
-
UPRSME
EORSME
WAKEUPE
EORSTE
SOFE
-
SUSPE
UDINT
-
UPRSMI
EORSMI
WAKEUPI
EORSTI
SOFI
-
SUSPI
UDCON
-
-
-
RPUTX
-
RSTCPU
RMWKUP
DETACH
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
USBCON
Reserved
Reserved
Reserved
Reserved
Reserved
CLKSTA
CLKSEL1
CLKSEL0
Reserved
UDR1
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
USBE
-
FRZCLK
-
-
-
-
-
page 195
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
EXTON
EXCKSEL0
CLKS
-
-
-
-
RCCKSEL1
EXSUT1
-
-
RCCKSEL0
EXSUT0
-
-
-
EXCKSEL2
EXTE
-
RCON
page 38
page 38
page 37
RCCKSEL3
RCSUT1
-
RCCKSEL2
RCSUT0
-
EXCKSEL3
EXCKSEL1
RCE
-
-
-
USART1 I/O Data Register
- USART1 Baud Rate Register High Byte
page 167
page 171
page 171
page 171
page 169
page 168
page 167
UBRR1H
UBRR1L
UCSR1D
UCSR1C
UCSR1B
UCSR1A
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
-
-
-
USART1 Baud Rate Register Low Byte
-
-
-
-
-
-
CTSEN
RTSEN
UMSEL11
UMSEL10
UPM11
UPM10
USBS1
UCSZ11
UCSZ10
UCPOL1
RXCIE1
TXCIE1
UDRIE1
RXEN1
TXEN1
UCSZ12
RXB81
TXB81
RXC1
TXC1
UDRE1
FE1
DOR1
PE1
U2X1
MPCM1
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
288
7799D–AVR–11/10
ATMEL [ ATMEL ]
