Figure 1-3.
Pinout ATmega1281/2561
PF6 (ADC6/TDO)
PF4 (ADC4/TCK)
PF5 (ADC5/TMS)
PF7 (ADC7/TDI)
PF0 (ADC0)
PF1 (ADC1)
PF2 (ADC2)
PF3 (ADC3)
PA0 (AD0)
PA1 (AD1)
50
64
63
62
61
60
59
58
57
56
55
54
53
52
51
(OC0B) PG5
(RXD0/PCINT8/PDI) PE0
(TXD0/PDO) PE1
(XCK0/AIN0) PE2
(OC3A/AIN1) PE3
(OC3B/INT4) PE4
(OC3C/INT5) PE5
(T3/INT6) PE6
(ICP3/CLKO/INT7) PE7
(SS/PCINT0) PB0
(SCK/ PCINT1) PB1
(MOSI/ PCINT2) PB2
(MISO/ PCINT3) PB3
(OC2A/ PCINT4) PB4
(OC1A/PCINT5) PB5
(OC1B/PCINT6) PB6
1
2
3
4
5
6
7
8
INDEX CORNER
49
PA2 (AD2)
AVCC
GND
AREF
GND
VCC
48
47
46
45
44
43
42
PA3 (AD3)
PA4 (AD4)
PA5 (AD5)
PA6 (AD6)
PA7 (AD7)
PG2 (ALE)
PC7 (A15)
PC6 (A14)
PC5 (A13)
PC4 (A12)
PC3 (A11)
PC2 (A10)
PC1 (A9)
PC0 (A8)
PG1 (RD)
PG0 (WR)
ATmega1281/2561
9
10
11
12
13
14
15
16
41
40
39
38
37
36
35
34
33
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
(T1) PD6
(RXD1/INT2) PD2
(SCL/INT0) PD0
(TXD1/INT3) PD3
(OC0A/OC1C/PCINT7) PB7
(XCK1) PD5
(ICP1) PD4
VCC
Note:
The large center pad underneath the QFN/MLF package is made of metal and internally con-
nected to GND. It should be soldered or glued to the board to ensure good mechanical stability. If
the center pad is left unconnected, the package might loosen from the board.
2. Disclaimer
Typical values contained in this datasheet are based on simulations and characterization of
other AVR microcontrollers manufactured on the same process technology. Min. and Max val-
ues will be available after the device is characterized.
4
ATmega640/1280/1281/2560/2561
2549L–AVR–08/07
(SDA/INT1) PD1
(TOSC2) PG3
(TOSC1) PG4
(T0) PD7
GND
XTAL2
RESET
XTAL1
32
ATMEL [ ATMEL CORPORATION ]
