ATmega48A/48PA/88A/88PA/168A/168PA/328/328P
Address
(0x7F)
(0x7E)
(0x7D)
(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)
Name
DIDR1
DIDR0
Reserved
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
Bit 7
–
–
–
REFS1
–
ADEN
Bit 6
–
–
–
REFS0
ACME
ADSC
Bit 5
–
ADC5D
–
ADLAR
–
ADATE
Bit 4
–
ADC4D
–
–
–
ADIF
Bit 3
–
ADC3D
–
MUX3
–
ADIE
Bit 2
–
ADC2D
–
MUX2
ADTS2
ADPS2
Bit 1
AIN1D
ADC1D
–
MUX1
ADTS1
ADPS1
Bit 0
AIN0D
ADC0D
–
MUX0
ADTS0
ADPS0
Page
250
267
263
266
264
266
266
ADC Data Register High byte
ADC Data Register Low byte
–
–
–
–
–
–
–
–
–
–
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
–
–
–
–
–
–
–
–
ICIE1
–
PCINT21
PCINT13
PCINT5
–
–
–
–
–
PRTIM0
–
–
–
WDP3
H
–
SP5
–
–
–
–
–
–
–
BODSE
(6)
–
–
–
–
ACO
–
–
DORD
–
–
–
–
–
–
–
–
–
–
PCINT20
PCINT12
PCINT4
–
–
–
–
–
–
–
–
–
WDCE
S
–
SP4
–
–
–
–
–
(RWWSRE)
5.
–
PUD
–
–
–
–
ACI
–
–
MSTR
–
–
–
–
–
–
–
–
–
–
PCINT19
PCINT11
PCINT3
–
ISC11
–
–
–
PRTIM1
–
–
CLKPS3
WDE
V
–
SP3
–
–
–
–
–
BLBSET
–
–
WDRF
SM2
–
–
ACIE
–
SPI Data Register
–
CPOL
–
CPHA
–
SPR1
SPI2X
SPR0
–
–
–
–
–
–
–
OCIE2B
OCIE1B
OCIE0B
PCINT18
PCINT10
PCINT2
–
ISC10
PCIE2
–
–
PRSPI
–
–
CLKPS2
WDP2
N
(SP10)
5.
SP2
–
–
–
–
–
PGWRT
–
–
BORF
SM1
–
–
ACIC
–
–
–
–
–
–
–
–
OCIE2A
OCIE1A
OCIE0A
PCINT17
PCINT9
PCINT1
–
ISC01
PCIE1
–
–
PRUSART0
–
–
CLKPS1
WDP1
Z
SP9
SP1
–
–
–
–
–
PGERS
–
IVSEL
EXTRF
SM0
–
–
ACIS1
–
–
–
–
–
–
–
–
TOIE2
TOIE1
TOIE0
PCINT16
PCINT8
PCINT0
–
ISC00
PCIE0
–
164
140
112
75
75
75
72
Oscillator Calibration Register
–
PRADC
–
–
CLKPS0
WDP0
C
SP8
SP0
–
–
–
–
–
SELFPRGEN
–
IVCE
PORF
SE
–
–
ACIS0
–
37
42
37
55
9
12
12
294
45/69/93
55
40
248
176
175
174
25
25
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)
FOC0A
COM0A1
TSM
FOC0B
COM0A0
–
–
COM0B1
–
–
COM0B0
–
WGM02
–
–
CS02
–
–
CS01
WGM01
PSRASY
CS00
WGM00
PSRSYNC
144/166
21
21
21
(EEPROM Address Register High Byte)
5.
EEPROM Address Register Low Byte
EEPROM Data Register
–
–
EEPM1
EEPM0
EERIE
EEMPE
EEPE
EERE
General Purpose I/O Register 0
21
25
10
8271BS–AVR–04/10