Data Sheet

622
ATmega48A/PA/88A/PA/168A/PA/328/P [DATASHEET]
Atmel-8271H-AVR- ATmega-Datasheet_08/2014
Note: 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 operate on 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.
4. When using the I/O specific commands IN and OUT, the I/O addresses 0x00 - 0x3F must be used. When addressing I/O
Registers as data space using LD and ST instructions, 0x20 must be added to these addresses. The
ATmega48A/PA/88A/PA/168A/PA/328/P is a complex microcontroller with more peripheral units than can be supported
within the 64 location reserved in Opcode for the IN and OUT instructions. For the Extended I/O space from 0x60 - 0xFF
in SRAM, only the ST/STS/STD and LD/LDS/LDD instructions can be used.
5. Only valid for ATmega88A/88PA/168A/168PA/328/328P.
6. BODS and BODSE only available for picoPower devices ATmega48PA/88PA/168PA/328P
0x15 (0x35) TIFR0 OCF0B OCF0A TOV0
0x14 (0x34) Reserved
0x13 (0x33) Reserved
0x12 (0x32) Reserved
0x11 (0x31) Reserved
0x10 (0x30) Reserved
0x0F (0x2F) Reserved
0x0E (0x2E) Reserved
0x0D (0x2D) Reserved
0x0C (0x2C) Reserved
0x0B (0x2B) PORTD PORTD7 PORTD6 PORTD5 PORTD4 PORTD3 PORTD2 PORTD1 PORTD0 93
0x0A (0x2A) DDRD DDD7 DDD6 DDD5 DDD4 DDD3 DDD2 DDD1 DDD0 93
0x09 (0x29) PIND PIND7 PIND6 PIND5 PIND4 PIND3 PIND2 PIND1 PIND0 93
0x08 (0x28) PORTC PORTC6 PORTC5 PORTC4 PORTC3 PORTC2 PORTC1 PORTC0 92
0x07 (0x27) DDRC DDC6 DDC5 DDC4 DDC3 DDC2 DDC1 DDC0 92
0x06 (0x26) PINC PINC6 PINC5 PINC4 PINC3 PINC2 PINC1 PINC0 93
0x05 (0x25) PORTB PORTB7 PORTB6 PORTB5 PORTB4 PORTB3 PORTB2 PORTB1 PORTB0 92
0x04 (0x24) DDRB DDB7 DDB6 DDB5 DDB4 DDB3 DDB2 DDB1 DDB0 92
0x03 (0x23) PINB PINB7 PINB6 PINB5 PINB4 PINB3 PINB2 PINB1 PINB0 92
0x02 (0x22) Reserved
0x01 (0x21) Reserved
0x0 (0x20) Reserved
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Page