427
8025I–AVR–02/09
ATmega48P/88P/168P/328P
(0x7F)
DIDR1
–
–
–
–
–
–
AIN1D
AIN0D
(0x7E)
DIDR0
–
–
ADC5D
ADC4D
ADC3D
ADC2D
ADC1D
ADC0D
(0x7D)
Reserved
–
–
–
–
–
–
–
–
(0x7C)
ADMUX
REFS1
REFS0
ADLAR
–
MUX3
MUX2
MUX1
MUX0
(0x7B)
ADCSRB
–
ACME
–
–
–
ADTS2
ADTS1
ADTS0
(0x7A)
ADCSRA
ADEN
ADSC
ADATE
ADIF
ADIE
ADPS2
ADPS1
ADPS0
(0x79)
ADCH
ADC Data Register High byte
(0x78)
ADCL
ADC Data Register Low byte
(0x77)
Reserved
–
–
–
–
–
–
–
–
(0x76)
Reserved
–
–
–
–
–
–
–
–
(0x75)
Reserved
–
–
–
–
–
–
–
–
(0x74)
Reserved
–
–
–
–
–
–
–
–
(0x73)
Reserved
–
–
–
–
–
–
–
–
(0x72)
Reserved
–
–
–
–
–
–
–
–
(0x71)
Reserved
–
–
–
–
–
–
–
–
(0x70)
TIMSK2
–
–
–
–
–
OCIE2B
OCIE2A
TOIE2
(0x6F)
TIMSK1
–
–
ICIE1
–
–
OCIE1B
OCIE1A
TOIE1
(0x6E)
TIMSK0
–
–
–
–
–
OCIE0B
OCIE0A
TOIE0
(0x6D)
PCMSK2
PCINT23
PCINT22
PCINT21
PCINT20
PCINT19
PCINT18
PCINT17
PCINT16
(0x6C)
PCMSK1
–
PCINT14
PCINT13
PCINT12
PCINT11
PCINT10
PCINT9
PCINT8
(0x6B)
PCMSK0
PCINT7
PCINT6
PCINT5
PCINT4
PCINT3
PCINT2
PCINT1
PCINT0
(0x6A)
Reserved
–
–
–
–
–
–
–
–
(0x69)
EICRA
–
–
–
–
ISC11
ISC10
ISC01
ISC00
(0x68)
PCICR
–
–
–
–
–
PCIE2
PCIE1
PCIE0
(0x67)
Reserved
–
–
–
–
–
–
–
–
(0x66)
OSCCAL
Oscillator Calibration Register
(0x65)
Reserved
–
–
–
–
–
–
–
–
(0x64)
PRR
PRTWI
PRTIM2
PRTIM0
–
PRTIM1
PRSPI
PRUSART0
PRADC
(0x63)
Reserved
–
–
–
–
–
–
–
–
(0x62)
Reserved
–
–
–
–
–
–
–
–
(0x61)
CLKPR
CLKPCE
–
–
–
CLKPS3
CLKPS2
CLKPS1
CLKPS0
(0x60)
WDTCSR
WDIF
WDIE
WDP3
WDCE
WDE
WDP2
WDP1
WDP0
0x3F (0x5F)
SREG
I
T
H
S
V
N
Z
C
0x3E (0x5E)
SPH
–
–
–
–
–
SP9
SP8
0x3D (0x5D)
SPL
SP7
SP6
SP5
SP4
SP3
SP2
SP1
SP0
0x3C (0x5C)
Reserved
–
–
–
–
–
–
–
–
0x3B (0x5B)
Reserved
–
–
–
–
–
–
–
–
0x3A (0x5A)
Reserved
–
–
–
–
–
–
–
–
0x39 (0x59)
Reserved
–
–
–
–
–
–
–
–
0x38 (0x58)
Reserved
–
–
–
–
–
–
–
–
0x37 (0x57)
SPMCSR
SPMIE
(RWWSB)
–
(RWWSRE)
BLBSET
PGWRT
PGERS
SELFPRGEN
0x36 (0x56)
Reserved
–
–
–
–
–
–
–
–
0x35 (0x55)
MCUCR
–
BODS
BODSE
PUD
–
–
IVSEL
IVCE
0x34 (0x54)
MCUSR
–
–
–
–
WDRF
BORF
EXTRF
PORF
0x33 (0x53)
SMCR
–
–
–
–
SM2
SM1
SM0
SE
0x32 (0x52)
Reserved
–
–
–
–
–
–
–
–
0x31 (0x51)
Reserved
–
–
–
–
–
–
–
–
0x30 (0x50)
ACSR
ACD
ACBG
ACO
ACI
ACIE
ACIC
ACIS1
ACIS0
0x2F (0x4F)
Reserved
–
–
–
–
–
–
–
–
0x2E (0x4E)
SPDR
SPI Data Register
0x2D (0x4D)
SPSR
SPIF
WCOL
–
–
–
–
–
SPI2X
0x2C (0x4C)
SPCR
SPIE
SPE
DORD
MSTR
CPOL
CPHA
SPR1
SPR0
0x2B (0x4B)
GPIOR2
General Purpose I/O Register 2
0x2A (0x4A)
GPIOR1
General Purpose I/O Register 1
0x29 (0x49)
Reserved
–
–
–
–
–
–
–
–
0x28 (0x48)
OCR0B
Timer/Counter0 Output Compare Register B
0x27 (0x47)
OCR0A
Timer/Counter0 Output Compare Register A
0x26 (0x46)
TCNT0
Timer/Counter0 (8-bit)
0x25 (0x45)
TCCR0B
FOC0A
FOC0B
–
–
WGM02
CS02
CS01
CS00
0x24 (0x44)
TCCR0A
COM0A1
COM0A0
COM0B1
COM0B0
–
–
WGM01
WGM00
0x23 (0x43)
GTCCR
TSM
–
–
–
–
–
PSRASY
PSRSYNC
0x22 (0x42)
EEARH
(EEPROM Address Register High Byte)
0x21 (0x41)
EEARL
EEPROM Address Register Low Byte
0x20 (0x40)
EEDR
EEPROM Data Register
0x1F (0x3F)
EECR
–
–
EEPM1
EEPM0
EERIE
EEMPE
EEPE
EERE
0x1E (0x3E)
GPIOR0
General Purpose I/O Register 0
Address
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
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