AI Interactive Datasheet ATtiny2313
AVR · tinyAVR

ATtiny2313 registers

All 54 registers by peripheral, at their data-space address (the I/O address IN and OUT use is shown beside it), with their reset value and every bit.

AC Analog Comparator

DIDRDigital Input Disable Register 1

Address
0x21 I/O 0x01
Reset
0x00
Access
read/write
  1. 7–
  2. 6–
  3. 5–
  4. 4–
  5. 3–
  6. 2–
  7. 1–
  8. 0–

ACSRAnalog Comparator Control And Status Register

Address
0x28 I/O 0x08
Reset
0x00
Access
read/write
  1. 7ACD
  2. 6ACBG
  3. 5ACO
  4. 4ACI
  5. 3ACIE
  6. 2ACIC
  7. 1ACIS1
  8. 0ACIS0
7 fields
FieldBitsWhat it does
ACD7Analog Comparator Disable
ACBG6Analog Comparator Bandgap Select
ACO5Analog Compare Output
ACI4Analog Comparator Interrupt Flag
ACIE3Analog Comparator Interrupt Enable
ACIC2
ACIS1:0Analog Comparator Interrupt Mode Select bits
  • 0 Interrupt on Toggle
  • 1 Reserved
  • 2 Interrupt on Falling Edge
  • 3 Interrupt on Rising Edge

USART USART

UBRRHUSART Baud Rate Register High Byte

Address
0x22 I/O 0x02
Reset
0x00
Access
read/write
  1. 7–
  2. 6–
  3. 5–
  4. 4–
  5. 3–
  6. 2–
  7. 1–
  8. 0–

UCSRCUSART Control and Status Register C

Address
0x23 I/O 0x03
Reset
0x00
Access
read/write
  1. 7–
  2. 6UMSEL
  3. 5UPM1
  4. 4UPM0
  5. 3USBS
  6. 2UCSZ1
  7. 1UCSZ0
  8. 0UCPOL
5 fields
FieldBitsWhat it does
UMSEL6USART Mode Select
  • 0 Asynchronous Operation
  • 1 Synchronous Operation
UPM5:4Parity Mode Bits
  • 0 Disabled
  • 1 Reserved
  • 2 Enabled, Even Parity
  • 3 Enabled, Odd Parity
USBS3Stop Bit Select
  • 0 1-bit
  • 1 2-bit
UCSZ2:1Character Size Bits
UCPOL0Clock Polarity

UBRRLUSART Baud Rate Register Low Byte

Address
0x29 I/O 0x09
Reset
0x00
Access
read/write
  1. 7–
  2. 6–
  3. 5–
  4. 4–
  5. 3–
  6. 2–
  7. 1–
  8. 0–

UCSRBUSART Control and Status Register B

Address
0x2A I/O 0x0A
Reset
0x00
Access
read/write
  1. 7RXCIE
  2. 6TXCIE
  3. 5UDRIE
  4. 4RXEN
  5. 3TXEN
  6. 2UCSZ2
  7. 1RXB8
  8. 0TXB8
8 fields
FieldBitsWhat it does
RXCIE7RX Complete Interrupt Enable
TXCIE6TX Complete Interrupt Enable
UDRIE5USART Data register Empty Interrupt Enable
RXEN4Receiver Enable
TXEN3Transmitter Enable
UCSZ22Character Size
RXB81Receive Data Bit 8
TXB80Transmit Data Bit 8

UCSRAUSART Control and Status Register A

Address
0x2B I/O 0x0B
Reset
0x00
Access
read/write
  1. 7RXC
  2. 6TXC
  3. 5UDRE
  4. 4FE
  5. 3DOR
  6. 2UPE
  7. 1U2X
  8. 0MPCM
8 fields
FieldBitsWhat it does
RXC7USART Receive Complete
TXC6USART Transmit Complete
UDRE5USART Data Register Empty
FE4Framing Error
DOR3Data Overrun
UPE2USART Parity Error
U2X1Double the USART Transmission Speed
MPCM0Multi-processor Communication Mode

UDRUSART I/O Data Register

Address
0x2C I/O 0x0C
Reset
0x00
Access
read/write
  1. 7–
  2. 6–
  3. 5–
  4. 4–
  5. 3–
  6. 2–
  7. 1–
  8. 0–

USI Universal Serial Interface

USICRUSI Control Register

Address
0x2D I/O 0x0D
Reset
0x00
Access
read/write
  1. 7USISIE
  2. 6USIOIE
  3. 5USIWM1
  4. 4USIWM0
  5. 3USICS1
  6. 2USICS0
  7. 1USICLK
  8. 0USITC
6 fields
FieldBitsWhat it does
USISIE7Start Condition Interrupt Enable
USIOIE6Counter Overflow Interrupt Enable
USIWM5:4USI Wire Mode Bits
  • 0 Normal Operation
  • 1 Three-Wire Mode
  • 2 Two-Wire Mode
  • 3 Two-Wire Mode Held Low
USICS3:2USI Clock Source Select Bits
USICLK1Clock Strobe
USITC0Toggle Clock Port Pin

USISRUSI Status Register

Address
0x2E I/O 0x0E
Reset
0x00
Access
read/write
  1. 7USISIF
  2. 6USIOIF
  3. 5USIPF
  4. 4USIDC
  5. 3USICNT3
  6. 2USICNT2
  7. 1USICNT1
  8. 0USICNT0
5 fields
FieldBitsWhat it does
USISIF7Start Condition Interrupt Flag
USIOIF6Counter Overflow Interrupt Flag
USIPF5Stop Condition Flag
USIDC4Data Output Collision
USICNT3:0USI Counter Value Bits

USIDRUSI Data Register

Address
0x2F I/O 0x0F
Reset
0x00
Access
read/write
  1. 7–
  2. 6–
  3. 5–
  4. 4–
  5. 3–
  6. 2–
  7. 1–
  8. 0–

PORTD I/O Port

PINDInput Pins, Port D

Address
0x30 I/O 0x10
Reset
0x00
Access
read/write
  1. 7–
  2. 6PIND6
  3. 5PIND5
  4. 4PIND4
  5. 3PIND3
  6. 2PIND2
  7. 1PIND1
  8. 0PIND0

DDRDData Direction Register, Port D

Address
0x31 I/O 0x11
Reset
0x00
Access
read/write
  1. 7–
  2. 6DDD6
  3. 5DDD5
  4. 4DDD4
  5. 3DDD3
  6. 2DDD2
  7. 1DDD1
  8. 0DDD0

PORTDData Register, Port D

Address
0x32 I/O 0x12
Reset
0x00
Access
read/write
  1. 7–
  2. 6PORTD6
  3. 5PORTD5
  4. 4PORTD4
  5. 3PORTD3
  6. 2PORTD2
  7. 1PORTD1
  8. 0PORTD0

CPU CPU Registers

GPIOR0General Purpose I/O Register 0

Address
0x33 I/O 0x13
Reset
0x00
Access
read/write
  1. 7–
  2. 6–
  3. 5–
  4. 4–
  5. 3–
  6. 2–
  7. 1–
  8. 0–

GPIOR1General Purpose I/O Register 1

Address
0x34 I/O 0x14
Reset
0x00
Access
read/write
  1. 7–
  2. 6–
  3. 5–
  4. 4–
  5. 3–
  6. 2–
  7. 1–
  8. 0–

GPIOR2General Purpose I/O Register 2

Address
0x35 I/O 0x15
Reset
0x00
Access
read/write
  1. 7–
  2. 6–
  3. 5–
  4. 4–
  5. 3–
  6. 2–
  7. 1–
  8. 0–

PCMSKPin-Change Mask register

Address
0x40 I/O 0x20
Reset
0x00
Access
read/write
  1. 7–
  2. 6–
  3. 5–
  4. 4–
  5. 3–
  6. 2–
  7. 1–
  8. 0–

GTCCRGeneral Timer Counter Control Register

Address
0x43 I/O 0x23
Reset
0x00
Access
read/write
  1. 7–
  2. 6–
  3. 5–
  4. 4–
  5. 3–
  6. 2–
  7. 1–
  8. 0PSR10
1 field
FieldBitsWhat it does
PSR100

CLKPRClock Prescale Register

Address
0x46 I/O 0x26
Reset
0x00
Access
read/write
  1. 7CLKPCE
  2. 6–
  3. 5–
  4. 4–
  5. 3CLKPS3
  6. 2CLKPS2
  7. 1CLKPS1
  8. 0CLKPS0
2 fields
FieldBitsWhat it does
CLKPCE7Clock Prescaler Change Enable
CLKPS3:0Clock Prescaler Select Bits
  • 0 1
  • 1 2
  • 2 4
  • 3 8
  • 4 16
  • 5 32
  • 6 64
  • 7 128
  • 8 256

OSCCALOscillator Calibration Register

Address
0x51 I/O 0x31
Reset
0x00
Access
read/write
  1. 7OSCCAL7
  2. 6OSCCAL6
  3. 5OSCCAL5
  4. 4OSCCAL4
  5. 3OSCCAL3
  6. 2OSCCAL2
  7. 1OSCCAL1
  8. 0OSCCAL0
1 field
FieldBitsWhat it does
OSCCAL7:0Oscillator Calibration

MCUSRMCU Status register

Address
0x54 I/O 0x34
Reset
0x00
Access
read/write
  1. 7–
  2. 6–
  3. 5–
  4. 4–
  5. 3WDRF
  6. 2BORF
  7. 1EXTRF
  8. 0PORF
4 fields
FieldBitsWhat it does
WDRF3Watchdog Reset Flag
BORF2Brown-out Reset Flag
EXTRF1External Reset Flag
PORF0Power-On Reset Flag

MCUCRMCU Control Register

Address
0x55 I/O 0x35
Reset
0x00
Access
read/write
  1. 7PUD
  2. 6SM2
  3. 5SE
  4. 4SM0
  5. 3ISC11
  6. 2ISC10
  7. 1ISC01
  8. 0ISC00
5 fields
FieldBitsWhat it does
PUD7Pull-up Disable
SM6,4Sleep Mode Select Bits
  • 0 Idle
  • 1 Power Down
  • 4 Standby
  • 5 Power Down
SE5Sleep Enable
ISC13:2Interrupt Sense Control 1 bits
  • 0 Low Level of INTX
  • 1 Any Logical Change in INTX
  • 2 Falling Edge of INTX
  • 3 Rising Edge of INTX
ISC01:0Interrupt Sense Control 0 bits
  • 0 Low Level of INTX
  • 1 Any Logical Change in INTX
  • 2 Falling Edge of INTX
  • 3 Rising Edge of INTX

SPMCSRStore Program Memory Control and Status register

Address
0x57 I/O 0x37
Reset
0x00
Access
read/write
  1. 7–
  2. 6–
  3. 5–
  4. 4CTPB
  5. 3RFLB
  6. 2PGWRT
  7. 1PGERS
  8. 0SPMEN
5 fields
FieldBitsWhat it does
CTPB4Clear Temporary Page Buffer
RFLB3Read Fuse and Lock Bits
PGWRT2Page Write
PGERS1Page Erase
SPMEN0Store Program Memory Enable

SPLStack Pointer Low Byte

Address
0x5D I/O 0x3D
Reset
0xDF
Access
read/write
  1. 7–
  2. 6–
  3. 5–
  4. 4–
  5. 3–
  6. 2–
  7. 1–
  8. 0–

SREGStatus Register

Address
0x5F I/O 0x3F
Reset
0x00
Access
read/write
  1. 7I
  2. 6T
  3. 5H
  4. 4S
  5. 3V
  6. 2N
  7. 1Z
  8. 0C
8 fields
FieldBitsWhat it does
I7Global Interrupt Enable
T6Bit Copy Storage
H5Half Carry Flag
S4Sign Bit
V3Two's Complement Overflow Flag
N2Negative Flag
Z1Zero Flag
C0Carry Flag

PORTB I/O Port

PINBPort B Input Pins

Address
0x36 I/O 0x16
Reset
0x00
Access
read/write
  1. 7PINB7
  2. 6PINB6
  3. 5PINB5
  4. 4PINB4
  5. 3PINB3
  6. 2PINB2
  7. 1PINB1
  8. 0PINB0

DDRBPort B Data Direction Register

Address
0x37 I/O 0x17
Reset
0x00
Access
read/write
  1. 7DDB7
  2. 6DDB6
  3. 5DDB5
  4. 4DDB4
  5. 3DDB3
  6. 2DDB2
  7. 1DDB1
  8. 0DDB0

PORTBPort B Data Register

Address
0x38 I/O 0x18
Reset
0x00
Access
read/write
  1. 7PORTB7
  2. 6PORTB6
  3. 5PORTB5
  4. 4PORTB4
  5. 3PORTB3
  6. 2PORTB2
  7. 1PORTB1
  8. 0PORTB0

PORTA I/O Port

PINAPort A Input Pins

Address
0x39 I/O 0x19
Reset
0x00
Access
read/write
  1. 7–
  2. 6–
  3. 5–
  4. 4–
  5. 3–
  6. 2PINA2
  7. 1PINA1
  8. 0PINA0

DDRAPort A Data Direction Register

Address
0x3A I/O 0x1A
Reset
0x00
Access
read/write
  1. 7–
  2. 6–
  3. 5–
  4. 4–
  5. 3–
  6. 2DDA2
  7. 1DDA1
  8. 0DDA0

PORTAPort A Data Register

Address
0x3B I/O 0x1B
Reset
0x00
Access
read/write
  1. 7–
  2. 6–
  3. 5–
  4. 4–
  5. 3–
  6. 2PORTA2
  7. 1PORTA1
  8. 0PORTA0

EEPROM EEPROM

EECREEPROM Control Register

Address
0x3C I/O 0x1C
Reset
0x00
Access
read/write
  1. 7–
  2. 6–
  3. 5EEPM1
  4. 4EEPM0
  5. 3EERIE
  6. 2EEMPE
  7. 1EEPE
  8. 0EERE
5 fields
FieldBitsWhat it does
EEPM5:4
  • 0 Erase and Write in one operation
  • 1 Erase Only
  • 2 Write Only
EERIE3EEProm Ready Interrupt Enable
EEMPE2EEPROM Master Write Enable
EEPE1EEPROM Write Enable
EERE0EEPROM Read Enable

EEDREEPROM Data Register

Address
0x3D I/O 0x1D
Reset
0x00
Access
read/write
  1. 7–
  2. 6–
  3. 5–
  4. 4–
  5. 3–
  6. 2–
  7. 1–
  8. 0–

EEAREEPROM Read/Write Access

Address
0x3E I/O 0x1E
Reset
0x00
Access
read/write
  1. 7–
  2. 6–
  3. 5–
  4. 4–
  5. 3–
  6. 2–
  7. 1–
  8. 0–

WDT Watchdog Timer

WDTCRWatchdog Timer Control Register

Address
0x41 I/O 0x21
Reset
0x00
Access
read/write
  1. 7WDIF
  2. 6WDIE
  3. 5WDP5
  4. 4WDCE
  5. 3WDE
  6. 2WDP2
  7. 1WDP1
  8. 0WDP0
5 fields
FieldBitsWhat it does
WDIF7Watchdog Timeout Interrupt Flag
WDIE6Watchdog Timeout Interrupt Enable
WDP5,2,1,0Watchdog Timer Prescaler Bits
  • 0 Oscillator Cycles 2K
  • 1 Oscillator Cycles 4K
  • 2 Oscillator Cycles 8K
  • 3 Oscillator Cycles 16K
  • 4 Oscillator Cycles 32K
  • 5 Oscillator Cycles 64K
  • 6 Oscillator Cycles 128K
  • 7 Oscillator Cycles 256K
  • 8 Oscillator Cycles 512K
  • 9 Oscillator Cycles 1024K
WDCE4Watchdog Change Enable
WDE3Watch Dog Enable

TC1 Timer/Counter, 16-bit

TCCR1CTimer/Counter1 Control Register C

Address
0x42 I/O 0x22
Reset
0x00
Access
read/write
  1. 7FOC1A
  2. 6FOC1B
  3. 5–
  4. 4–
  5. 3–
  6. 2–
  7. 1–
  8. 0–
2 fields
FieldBitsWhat it does
FOC1A7Force Output Compare for Channel A
FOC1B6Force Output Compare for Channel B

ICR1Timer/Counter1 Input Capture Register Bytes

Address
0x44 I/O 0x24
Reset
0x0000
Access
read/write
Size
16-bit

OCR1BTimer/Counter1 Output Compare Register Bytes

Address
0x48 I/O 0x28
Reset
0x0000
Access
read/write
Size
16-bit

OCR1ATimer/Counter1 Output Compare Register Bytes

Address
0x4A I/O 0x2A
Reset
0x0000
Access
read/write
Size
16-bit

TCNT1Timer/Counter1 Bytes

Address
0x4C I/O 0x2C
Reset
0x0000
Access
read/write
Size
16-bit

TCCR1BTimer/Counter1 Control Register B

Address
0x4E I/O 0x2E
Reset
0x00
Access
read/write
  1. 7ICNC1
  2. 6ICES1
  3. 5–
  4. 4WGM11
  5. 3WGM10
  6. 2CS12
  7. 1CS11
  8. 0CS10
4 fields
FieldBitsWhat it does
ICNC17Input Capture 1 Noise Canceler
ICES16Input Capture 1 Edge Select
WGM14:3Waveform Generation Mode Bits
CS12:0Clock Select1 bits
  • 0 No Clock Source (Stopped)
  • 1 Running, No Prescaling
  • 2 Running, CLK/8
  • 3 Running, CLK/64
  • 4 Running, CLK/256
  • 5 Running, CLK/1024
  • 6 Running, ExtClk Tn Falling Edge
  • 7 Running, ExtClk Tn Rising Edge

TCCR1ATimer/Counter1 Control Register A

Address
0x4F I/O 0x2F
Reset
0x00
Access
read/write
  1. 7COM1A1
  2. 6COM1A0
  3. 5COM1B1
  4. 4COM1B0
  5. 3–
  6. 2–
  7. 1WGM11
  8. 0WGM10
3 fields
FieldBitsWhat it does
COM1A7:6Compare Output Mode 1A, bits
COM1B5:4Compare Output Mode 1B, bits
WGM11:0Pulse Width Modulator Select Bits

TIFRTimer/Counter Interrupt Flag register

Address
0x58 I/O 0x38
Reset
0x00
Access
read/write
  1. 7TOV1
  2. 6OCF1A
  3. 5OCF1B
  4. 4–
  5. 3ICF1
  6. 2–
  7. 1–
  8. 0–
4 fields
FieldBitsWhat it does
TOV17Timer/Counter1 Overflow Flag
OCF1A6Output Compare Flag 1A
OCF1B5Output Compare Flag 1B
ICF13Input Capture Flag 1

TIMSKTimer/Counter Interrupt Mask Register

Address
0x59 I/O 0x39
Reset
0x00
Access
read/write
  1. 7TOIE1
  2. 6OCIE1A
  3. 5OCIE1B
  4. 4–
  5. 3ICIE1
  6. 2–
  7. 1–
  8. 0–
4 fields
FieldBitsWhat it does
TOIE17Timer/Counter1 Overflow Interrupt Enable
OCIE1A6Timer/Counter1 Output CompareA Match Interrupt Enable
OCIE1B5Timer/Counter1 Output CompareB Match Interrupt Enable
ICIE13Timer/Counter1 Input Capture Interrupt Enable

TC0 Timer/Counter, 8-bit

TCCR0ATimer/Counter Control Register A

Address
0x50 I/O 0x30
Reset
0x00
Access
read/write
  1. 7COM0A1
  2. 6COM0A0
  3. 5COM0B1
  4. 4COM0B0
  5. 3–
  6. 2–
  7. 1WGM01
  8. 0WGM00
3 fields
FieldBitsWhat it does
COM0A7:6Compare Match Output A Mode
COM0B5:4Compare Match Output B Mode
WGM01:0Waveform Generation Mode

TCNT0Timer/Counter0

Address
0x52 I/O 0x32
Reset
0x00
Access
read/write
  1. 7–
  2. 6–
  3. 5–
  4. 4–
  5. 3–
  6. 2–
  7. 1–
  8. 0–

TCCR0BTimer/Counter Control Register B

Address
0x53 I/O 0x33
Reset
0x00
Access
read/write
  1. 7FOC0A
  2. 6FOC0B
  3. 5–
  4. 4–
  5. 3WGM02
  6. 2CS02
  7. 1CS01
  8. 0CS00
4 fields
FieldBitsWhat it does
FOC0A7Force Output Compare B
FOC0B6Force Output Compare B
WGM023
CS02:0Clock Select
  • 0 No Clock Source (Stopped)
  • 1 Running, No Prescaling
  • 2 Running, CLK/8
  • 3 Running, CLK/64
  • 4 Running, CLK/256
  • 5 Running, CLK/1024
  • 6 Running, ExtClk Tn Falling Edge
  • 7 Running, ExtClk Tn Rising Edge

OCR0ATimer/Counter0 Output Compare Register

Address
0x56 I/O 0x36
Reset
0x00
Access
read/write
  1. 7–
  2. 6–
  3. 5–
  4. 4–
  5. 3–
  6. 2–
  7. 1–
  8. 0–

TIFRTimer/Counter Interrupt Flag register

Address
0x58 I/O 0x38
Reset
0x00
Access
read/write
  1. 7–
  2. 6–
  3. 5–
  4. 4–
  5. 3–
  6. 2OCF0B
  7. 1TOV0
  8. 0OCF0A
3 fields
FieldBitsWhat it does
OCF0B2Timer/Counter0 Output Compare Flag 0B
TOV01Timer/Counter0 Overflow Flag
OCF0A0Timer/Counter0 Output Compare Flag 0A

TIMSKTimer/Counter Interrupt Mask Register

Address
0x59 I/O 0x39
Reset
0x00
Access
read/write
  1. 7–
  2. 6–
  3. 5–
  4. 4–
  5. 3–
  6. 2OCIE0B
  7. 1TOIE0
  8. 0OCIE0A
3 fields
FieldBitsWhat it does
OCIE0B2Timer/Counter0 Output Compare Match B Interrupt Enable
TOIE01Timer/Counter0 Overflow Interrupt Enable
OCIE0A0Timer/Counter0 Output Compare Match A Interrupt Enable

OCR0BTimer/Counter0 Output Compare Register

Address
0x5C I/O 0x3C
Reset
0x00
Access
read/write
  1. 7–
  2. 6–
  3. 5–
  4. 4–
  5. 3–
  6. 2–
  7. 1–
  8. 0–

EXINT External Interrupts

EIFRExtended Interrupt Flag Register

Address
0x5A I/O 0x3A
Reset
0x00
Access
read/write
  1. 7INTF1
  2. 6INTF0
  3. 5PCIF
  4. 4–
  5. 3–
  6. 2–
  7. 1–
  8. 0–
2 fields
FieldBitsWhat it does
INTF7:6External Interrupt Flags
PCIF5

GIMSKGeneral Interrupt Mask Register

Address
0x5B I/O 0x3B
Reset
0x00
Access
read/write
  1. 7INT1
  2. 6INT0
  3. 5PCIE
  4. 4–
  5. 3–
  6. 2–
  7. 1–
  8. 0–
2 fields
FieldBitsWhat it does
INT7:6External Interrupt Request 1 Enable
PCIE5