Datasheet

7766FS–AVR–11/10

ATmega16/32U4

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 $00 - $1F are directly bit-accessible using the SBI and CBI instructions. In these reg-

isters, 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 the CBI and SBI instructions will operate on

all bits in the I/O register, writing a one back into any flag read as set, thus clearing the flag. 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 $00 - $3F must be used. When addressing I/O regis-

ters as data space using LD and ST instructions, $20 must be added to these addresses. The ATmega16U4/ATmega32U4 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 $60 - $1FF in SRAM, only the ST/STS/STD and LD/LDS/LDD

instructions can be used.

0x1B (0x3B) PCIFR - - - - - - -PCIF0

0x1A (0x3A) Reserved - - - - - - - -

0x19 (0x39) TIFR4 OCF4D OCF4A OCF4B - -TOV4 - -

0x18 (0x38) TIFR3 - - ICF3 - OCF3C OCF3B OCF3A TOV3

0x17 (0x37) Reserved - - - - - - - -

0x16 (0x36) TIFR1

- - ICF1 - OCF1C OCF1B OCF1A TOV1

0x15 (0x35) TIFR0

- - - - - OCF0B OCF0A TOV0

0x14 (0x34) Reserved - - - - - - - -

0x13 (0x33) Reserved - - - - - - - -

0x12 (0x32) Reserved - - - - - - - -

0x11 (0x31) PORTF PORTF7 PORTF6 PORTF5 PORTF4 - - PORTF1 PORTF0

0x10 (0x30) DDRF DDF7 DDF6 DDF5 DDF4 - - DDF1 DDF0

0x0F (0x2F) PINF PINF7 PINF6 PINF5 PINF4 - - PINF1 PINF0

0x0E (0x2E) PORTE - PORTE6 - - - PORTE2 - -

0x0D (0x2D) DDRE - DDE6 - - - DDE2 - -

0x0C (0x2C) PINE - PINE6 - - - PINE2 - -

0x0B (0x2B) PORTD PORTD7 PORTD6 PORTD5 PORTD4 PORTD3 PORTD2 PORTD1 PORTD0

0x0A (0x2A) DDRD

DDD7 DDD6 DDD5 DDD4 DDD3 DDD2 DDD1 DDD0

0x09 (0x29) PIND

PIND7 PIND6 PIND5 PIND4 PIND3 PIND2 PIND1 PIND0

0x08 (0x28) PORTC PORTC7 PORTC6 - - - - - -

0x07 (0x27) DDRC DDC7 DDC6 - - - - - -

0x06 (0x26) PINC PINC7 PINC6 - - - - - -

0x05 (0x25) PORTB PORTB7 PORTB6 PORTB5 PORTB4 PORTB3 PORTB2 PORTB1 PORTB0

0x04 (0x24) DDRB DDB7 DDB6 DDB5 DDB4 DDB3 DDB2 DDB1 DDB0

0x03 (0x23) PINB PINB7 PINB6 PINB5 PINB4 PINB3 PINB2 PINB1 PINB0

0x02 (0x22) Reserved - - - - - - - -

0x01 (0x21) Reserved - - - - - - - -

0x00 (0x20) Reserved - - - - - - - -

Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Page