ATmega 2560 - pin mapping

In the image below you can see the PIN mapping for the Atmega2560. 
The chip used is the Arduino 2560. 
You can also find mappings for Atmega8 and Atmega 168/328 as well.

Atmega8 and Atmega 168/328 mapping

Pin Number Pin Name Mapped Pin Name
1 PG5 ( OC0B ) Digital pin 4 (PWM)
2 PE0 ( RXD0/PCINT8 ) Digital pin 0 (RX0)
3 PE1 ( TXD0 ) Digital pin 1 (TX0)
4 PE2 ( XCK0/AIN0 )  
5 PE3 ( OC3A/AIN1 ) Digital pin 5 (PWM)
6 PE4 ( OC3B/INT4 ) Digital pin 2 (PWM)
7 PE5 ( OC3C/INT5 ) Digital pin 3 (PWM)
8 PE6 ( T3/INT6 )  
9 PE7 ( CLKO/ICP3/INT7 )  
10 VCC VCC
11 GND GND
12 PH0 ( RXD2 ) Digital pin 17 (RX2)
13 PH1 ( TXD2 ) Digital pin 16 (TX2)
14 PH2 ( XCK2 )  
15 PH3 ( OC4A ) Digital pin 6 (PWM)
16 PH4 ( OC4B ) Digital pin 7 (PWM)
17 PH5 ( OC4C ) Digital pin 8 (PWM)
18 PH6 ( OC2B ) Digital pin 9 (PWM)
19 PB0 ( SS/PCINT0 ) Digital pin 53 (SS)
20 PB1 ( SCK/PCINT1 ) Digital pin 52 (SCK)
21 PB2 ( MOSI/PCINT2 ) Digital pin 51 (MOSI)
22 PB3 ( MISO/PCINT3 ) Digital pin 50 (MISO)
23 PB4 ( OC2A/PCINT4 ) Digital pin 10 (PWM)
24 PB5 ( OC1A/PCINT5 ) Digital pin 11 (PWM)
25 PB6 ( OC1B/PCINT6 ) Digital pin 12 (PWM)
26 PB7 ( OC0A/OC1C/PCINT7 ) Digital pin 13 (PWM)
27 PH7 ( T4 )  
28 PG3 ( TOSC2 )  
29 PG4 ( TOSC1 )  
30 RESET RESET
31 VCC VCC
32 GND GND
33 XTAL2 XTAL2
34 XTAL1 XTAL1
35 PL0 ( ICP4 ) Digital pin 49
36 PL1 ( ICP5 ) Digital pin 48
37 PL2 ( T5 ) Digital pin 47
38 PL3 ( OC5A ) Digital pin 46 (PWM)
39 PL4 ( OC5B ) Digital pin 45 (PWM)
40 PL5 ( OC5C ) Digital pin 44 (PWM)
41 PL6 Digital pin 43
42 PL7 Digital pin 42
43 PD0 ( SCL/INT0 ) Digital pin 21 (SCL)
44 PD1 ( SDA/INT1 ) Digital pin 20 (SDA)
45 PD2 ( RXDI/INT2 ) Digital pin 19 (RX1)
46 PD3 ( TXD1/INT3 ) Digital pin 18 (TX1)
47 PD4 ( ICP1 )  
48 PD5 ( XCK1 )  
49 PD6 ( T1 )  
50 PD7 ( T0 ) Digital pin 38
51 PG0 ( WR ) Digital pin 41
52 PG1 ( RD ) Digital pin 40
53 PC0 ( A8 ) Digital pin 37
54 PC1 ( A9 ) Digital pin 36
55 PC2 ( A10 ) Digital pin 35
56 PC3 ( A11 ) Digital pin 34
57 PC4 ( A12 ) Digital pin 33
58 PC5 ( A13 ) Digital pin 32
59 PC6 ( A14 ) Digital pin 31
60 PC7 ( A15 ) Digital pin 30
61 VCC VCC
62 GND GND
63 PJ0 ( RXD3/PCINT9 ) Digital pin 15 (RX3)
64 PJ1 ( TXD3/PCINT10 ) Digital pin 14 (TX3)
65 PJ2 ( XCK3/PCINT11 )  
66 PJ3 ( PCINT12 )  
67 PJ4 ( PCINT13 )  
68 PJ5 ( PCINT14 )  
69 PJ6 ( PCINT 15 )  
70 PG2 ( ALE ) Digital pin 39
71 PA7 ( AD7 ) Digital pin 29
72 PA6 ( AD6 ) Digital pin 28
73 PA5 ( AD5 ) Digital pin 27
74 PA4 ( AD4 ) Digital pin 26
75 PA3 ( AD3 ) Digital pin 25
76 PA2 ( AD2 ) Digital pin 24
77 PA1 ( AD1 ) Digital pin 23
78 PA0 ( AD0 ) Digital pin 22
79 PJ7  
80 VCC VCC
81 GND GND
82 PK7 ( ADC15/PCINT23 ) Analog pin 15
83 PK6 ( ADC14/PCINT22 ) Analog pin 14
84 PK5 ( ADC13/PCINT21 ) Analog pin 13
85 PK4 ( ADC12/PCINT20 ) Analog pin 12
86 PK3 ( ADC11/PCINT19 ) Analog pin 11
87 PK2 ( ADC10/PCINT18 ) Analog pin 10
88 PK1 ( ADC9/PCINT17 ) Analog pin 9
89 PK0 ( ADC8/PCINT16 ) Analog pin 8
90 PF7 ( ADC7 ) Analog pin 7
91 PF6 ( ADC6 ) Analog pin 6
92 PF5 ( ADC5/TMS ) Analog pin 5
93 PF4 ( ADC4/TMK ) Analog pin 4
94 PF3 ( ADC3 ) Analog pin 3
95 PF2 ( ADC2 ) Analog pin 2
96 PF1 ( ADC1 ) Analog pin 1
97 PF0 ( ADC0 ) Analog pin 0
98 AREF Analog Reference
99 GND GND
100 AVCC VCC

Published under Creative Commons Attribution ShareAlike 3.0. Based on the reference originally written byarduino.cc