Address
(0x7C)
(0x7B)
(0x7A)
(0x79)
(0x78)
(0x77)
(0x76)
(0x75)
(0x74)
(0x73)
(0x72)
(0x71)
(0x70)
(0x6F)
(0x6E)
(0x6D)
(0x6C)
(0x6B)
(0x6A)
(0x69)
(0x68)
(0x67)
(0x66)
(0x65)
(0x64)
(0x63)
(0x62)
(0x61)
(0x60)
0x3F (0x5F)
0x3E (0x5E)
0x3D (0x5D)
0x3C (0x5C)
0x3B (0x5B)
0x3A (0x5A)
0x39 (0x59)
0x38 (0x58)
0x37 (0x57)
0x36 (0x56)
0x35 (0x55)
0x34 (0x54)
0x33 (0x53)
0x32 (0x52)
0x31 (0x51)
0x30 (0x50)
0x2F (0x4F)
0x2E (0x4E)
0x2D (0x4D)
0x2C (0x4C)
0x2B (0x4B)
0x2A (0x4A)
0x29 (0x49)
0x28 (0x48)
0x27 (0x47)
0x26 (0x46)
0x25 (0x45)
0x24 (0x44)
0x23 (0x43)
0x22 (0x42)
0x21 (0x41)
0x20 (0x40)
0x1F (0x3F)
0x1E (0x3E)
0x1D (0x3D)
0x1C (0x3C)
0x1B (0x3B)
0x1A (0x3A)
0x19 (0x39)
Name
ADMUX
ADCSRB
ADCSRA
ADCH
ADCL
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
TIMSK2
TIMSK1
TIMSK0
PCMSK2
PCMSK1
PCMSK0
Reserved
EICRA
PCICR
Reserved
OSCCAL
Reserved
PRR
Reserved
Reserved
CLKPR
WDTCSR
SREG
SPH
SPL
Reserved
Reserved
Reserved
Reserved
Reserved
SPMCSR
Reserved
MCUCR
MCUSR
SMCR
Reserved
Reserved
ACSR
Reserved
SPDR
SPSR
SPCR
GPIOR2
GPIOR1
Reserved
OCR0B
OCR0A
TCNT0
TCCR0B
TCCR0A
GTCCR
EEARH
EEARL
EEDR
EECR
GPIOR0
EIMSK
EIFR
PCIFR
Reserved
Reserved
Bit 7
REFS1
–
ADEN
Bit 6
REFS0
ACME
ADSC
–
–
–
–
–
–
–
–
–
–
PCINT23
–
PCINT7
–
–
–
–
–
PRTWI
–
–
CLKPCE
WDIF
I
–
SP7
–
–
–
–
–
SPMIE
–
–
–
–
–
–
ACD
–
SPIF
SPIE
–
–
–
–
–
–
–
–
–
–
PCINT22
PCINT14
PCINT6
–
–
–
–
–
PRTIM2
–
–
–
WDIE
T
–
SP6
–
–
–
–
–
(RWWSB)5.
–
BODS(6)
–
–
–
–
ACBG
–
WCOL
SPE
–
–
FOC0A
COM0A1
TSM
FOC0B
COM0A0
–
–
–
–
–
–
–
–
–
–
–
–
–
Bit 5
Bit 4
Bit 3
Bit 2
ADLAR
–
ADATE
–
–
–
–
–
–
–
–
ICIE1
–
PCINT21
PCINT13
PCINT5
–
–
–
–
–
PRTIM0
–
–
–
WDP3
H
–
SP5
–
–
–
–
–
SIGRD
–
BODSE(6)
–
–
–
–
ACO
–
–
DORD
–
–
COM0B1
–
EEPM1
–
–
–
–
–
–
MUX3
MUX2
–
–
ADTS2
ADIF
ADIE
ADPS2
ADC Data Register High byte
ADC Data Register Low byte
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
OCIE2B
–
–
OCIE1B
–
–
OCIE0B
PCINT20
PCINT19
PCINT18
PCINT12
PCINT11
PCINT10
PCINT4
PCINT3
PCINT2
–
–
–
–
ISC11
ISC10
–
–
PCIE2
–
–
–
Oscillator Calibration Register
–
–
–
–
PRTIM1
PRSPI
–
–
–
–
–
–
–
CLKPS3
CLKPS2
WDCE
WDE
WDP2
S
V
N
–
–
(SP10) 5.
SP4
SP3
SP2
–
–
–
–
–
–
–
–
–
–
–
–
–
(RWWSRE)5.
–
BLBSET
–
PGWRT
–
–
–
PUD
–
–
–
WDRF
BORF
–
SM2
SM1
–
–
–
–
–
–
ACI
ACIE
ACIC
–
–
–
SPI Data Register
–
–
–
MSTR
CPOL
CPHA
General Purpose I/O Register 2
General Purpose I/O Register 1
–
–
–
Timer/Counter0 Output Compare Register B
Timer/Counter0 Output Compare Register A
Timer/Counter0 (8-bit)
–
WGM02
CS02
COM0B0
–
–
–
–
–
(EEPROM Address Register High Byte) 5.
EEPROM Address Register Low Byte
EEPROM Data Register
EEPM0
EERIE
EEMPE
General Purpose I/O Register 0
–
–
–
–
–
–
–
–
PCIF2
–
–
–
–
–
–
Bit 1
MUX1
ADTS1
ADPS1
–
–
–
–
–
–
–
OCIE2A
OCIE1A
OCIE0A
PCINT17
PCINT9
PCINT1
–
ISC01
PCIE1
–
–
PRUSART0
–
–
CLKPS1
WDP1
Z
SP9
SP1
–
–
–
–
–
PGERS
–
IVSEL
EXTRF
SM0
–
–
ACIS1
–
–
SPR1
–
CS01
WGM01
PSRASY
EEPE
INT1
INTF1
PCIF1
–
–
Bit 0
MUX0
ADTS0
ADPS0
–
–
–
–
–
–
–
TOIE2
TOIE1
TOIE0
PCINT16
PCINT8
PCINT0
–
ISC00
PCIE0
–
–
PRADC
–
–
CLKPS0
WDP0
C
SP8
SP0
–
–
–
–
–
SPMEN
–
IVCE
PORF
SE
–
–
ACIS0
–
SPI2X
SPR0
–
CS00
WGM00
PSRSYNC
EERE
INT0
INTF0
PCIF0
–
–
Page
248
251
249
250
250
157
135
109
74
74
74
71
37
42
37
54
10
13
13
278
45/68/91
54
40
235
169
168
167
26
26
140/159
22
22
22
22
26
72
72
ATmega48A/PA/88A/PA/168A/PA/328/P [DATASHEET]
11
Atmel-8271IS-AVR- ATmega-Datasheet_10/2014