182
7598H–AVR–07/09
ATtiny25/45/85
24. Register Summary
Address
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Page
0x3F
SREG
I
T
H
S
V
N
Z
C
0x3E
SPH
–
–
–
–
–
–
–
SP8
0x3D
SPL
SP7
SP6
SP5
SP4
SP3
SP2
SP1
SP0
0x3C
Reserved
–
0x3B
GIMSK
–
INT0
PCIE
–
–
–
–
–
0x3A GIFR
–
INTF0
PCIF
–
–
–
–
–
0x39 TIMSK
–
OCIE1A
OCIE1B
OCIE0A
OCIE0B
TOIE1
TOIE0
–
0x38 TIFR
–
OCF1A
OCF1B
OCF0A
OCF0B
TOV1
TOV0
–
0x37 SPMCSR
–
–
–
CTPB
RFLB
PGWRT
PGERS
SPMEN
0x36 Reserved
–
0x35
MCUCR
BODS
PUD
SE
SM1
SM0
BODSE
ISC01
ISC00
0x34 MCUSR
–
–
–
–
WDRF
BORF
EXTRF
PORF
0x33 TCCR0B
FOC0A
FOC0B
–
–
WGM02
CS02
CS01
CS00
0x32 TCNT0
Timer/Counter0
0x31 OSCCAL
Oscillator
Calibration Register
0x30 TCCR1
CTC1
PWM1A
COM1A1
COM1A0
CS13
CS12
CS11
CS10
0x2F
TCNT1
Timer/Counter1
0x2E
OCR1A
Timer/Counter1 Output Compare Register A
0x2D
OCR1C
Timer/Counter1 Output Compare Register C
0x2C
GTCCR
TSM
PWM1B
COM1B1
COM1B0
FOC1B
FOC1A
PSR1
PSR0
0x2B
OCR1B
Timer/Counter1 Output Compare Register B
0x2A TCCR0A
COM0A1
COM0A0
COM0B1
COM0B0
–
WGM01
WGM00
0x29
OCR0A
Timer/Counter0 – Output Compare Register A
0x28
OCR0B
Timer/Counter0 – Output Compare Register B
0x27 PLLCSR
SM
–
–
–
–
PCKE
PLLE
PLOCK
0x26 CLKPR
CLKPCE
–
–
–
CLKPS3
CLKPS2
CLKPS1
CLKPS0
0x25
DT1A
DT1AH3
DT1AH2
DT1AH1
DT1AH0
DT1AL3
DT1AL2
DT1AL1
DT1AL0
0x24 DT1B
DT1BH3
DT1BH2
DT1BH1
DT1BH0
DT1BL3
DT1BL2
DT1BL1
DT1BL0
0x23 DTPS1
-
-
-
-
-
-
DTPS11
DTPS10
0x22
DWDR
DWDR[7:0]
0x21 WDTCR
WDTIF
WDTIE
WDP3
WDCE
WDE
WDP2
WDP1
WDP0
0x20 PRR
–
PRTIM1
PRTIM0
PRUSI
PRADC
0x1F EEARH
EEAR8
0x1E
EEARL
EEAR7
EEAR6
EEAR5
EEAR4
EEAR3
EEAR2
EEAR1
EEAR0
0x1D
EEDR
EEPROM Data Register
0x1C
EECR
–
–
EEPM1
EEPM0
EERIE
EEMWE
EEWE
EERE
0x1B Reserved
–
0x1A
Reserved
–
0x19 Reserved
–
0x18 PORTB
–
–
PORTB5
PORTB4
PORTB3
PORTB2
PORTB1
PORTB0
0x17
DDRB
–
–
DDB5
DDB4
DDB3
DDB2
DDB1
DDB0
0x16 PINB
–
–
PINB5
PINB4
PINB3
PINB2
PINB1
PINB0
0x15
PCMSK
–
–
PCINT5
PCINT4
PCINT3
PCINT2
PCINT1
PCINT0
0x14 DIDR0
–
–
ADC0D
ADC2D
ADC3D
ADC1D
EIN1D
AIN0D
0x13
GPIOR2
General Purpose I/O Register 2
0x12
GPIOR1
General Purpose I/O Register 1
0x11
GPIOR0
General Purpose I/O Register 0
0x10
USIBR
USI Buffer Register
0x0F
USIDR
USI Data Register
0x0E USISR
USICIF
USIOIF
USIPF
USIDC
USICNT3
USICNT2
USICNT1
USICNT0
0x0D
USICR
USISIE
USIOIE
USIWM1
USIWM0
USICS1
USICS0
USICLK
USITC
0x0C
Reserved
–
0x0B
Reserved
–
0x0A
Reserved
–
0x09
Reserved
–
Notes:
1. For compatibility with future devices, reserved bits should be written to zero if accessed. Reserved I/O memory
addresses should never be written.
2. I/O Registers within the address range 0x00 - 0x1F are directly bit-accessible using the SBI and CBI instructions. In these
registers, the value of single bits can be checked by using the SBIS and SBIC instructions.
3. Some of the Status Flags are cleared by writing a logical one to them. Note that, unlike most other AVRs, the CBI and SBI
instructions will only operation the specified bit, and can therefore be used on registers containing such Status Flags. The
CBI and SBI instructions work with registers 0x00 to 0x1F only.