ATmega2560 pinout

Package pin assignments for ATmega2560, with peripheral signals, clock grades and a serial programming guide.

TQFP-100 100 contacts

CBGA-100

100 contacts Current package

Microchip Technology · 100 numbered contacts. See the individual package drawings for footprint dimensions.

CBGA-100 pinout

12345678910 A B C D E F G H J K

Transparent top view · A1 at the upper left Scroll the map to reach all contacts.

Selected pin details

F5 · PL4

Bidirectional · GPIO

General-purpose digital I/O. Alternate assignments: OCB (TC5).

After reset · GPIO driver is high impedance during reset. Clock, debug, and alternate-function use depend on fuse and peripheral configuration.

2549Q · Pinout and peripheral signal descriptions

Electrical limits · Link to this pin

All 100 pins

Pin	Signal	Direction	Function
A1	GND Return	Return	Supply return. Connect every ground pin.
A2	AREF Analog reference	Analog reference	ADC voltage reference terminal. Check the reference selection before driving this pin from an external voltage.
A3	PF0 Bidirectional	Bidirectional	General-purpose digital I/O. Alternate assignments: ADC0 (ADC).
A4	PF2 Bidirectional	Bidirectional	General-purpose digital I/O. Alternate assignments: ADC2 (ADC).
A5	PF5 Bidirectional	Bidirectional	General-purpose digital I/O. Alternate assignments: TMS (JTAG), ADC5 (ADC).
A6	PK0 Bidirectional	Bidirectional	General-purpose digital I/O. Alternate assignments: PCINT16 (EXINT), ADC8 (ADC).
A7	PK3 Bidirectional	Bidirectional	General-purpose digital I/O. Alternate assignments: PCINT19 (EXINT), ADC11 (ADC).
A8	PK6 Bidirectional	Bidirectional	General-purpose digital I/O. Alternate assignments: PCINT22 (EXINT), ADC14 (ADC).
A9	GND Return	Return	Supply return. Connect every ground pin.
A10	VCC Supply	Supply	Digital supply. Connect every VCC pin and place a local 100 nF ceramic bypass close to each VCC-to-ground pair.
B1	AVCC Supply	Supply	Analog supply. Connect it to the supply even if analog conversion is unused. Follow the data sheet’s filtering guidance for precision conversion.
B2	PG5 Bidirectional	Bidirectional	General-purpose digital I/O. Alternate assignments: OCB (TC0).
B3	PF1 Bidirectional	Bidirectional	General-purpose digital I/O. Alternate assignments: ADC1 (ADC).
B4	PF3 Bidirectional	Bidirectional	General-purpose digital I/O. Alternate assignments: ADC3 (ADC).
B5	PF6 Bidirectional	Bidirectional	General-purpose digital I/O. Alternate assignments: TDO (JTAG), ADC6 (ADC).
B6	PK1 Bidirectional	Bidirectional	General-purpose digital I/O. Alternate assignments: PCINT17 (EXINT), ADC9 (ADC).
B7	PK4 Bidirectional	Bidirectional	General-purpose digital I/O. Alternate assignments: PCINT20 (EXINT), ADC12 (ADC).
B8	PK7 Bidirectional	Bidirectional	General-purpose digital I/O. Alternate assignments: PCINT23 (EXINT), ADC15 (ADC).
B9	PA0 Bidirectional	Bidirectional	General-purpose digital I/O.
B10	PA2 Bidirectional	Bidirectional	General-purpose digital I/O.
C1	PE2 Bidirectional	Bidirectional	General-purpose digital I/O. Alternate assignments: AIN0 (AC), XCK (USART0).
C2	PE0 Bidirectional	Bidirectional	General-purpose digital I/O. Alternate assignments: RXD (USART0), PCINT8 (EXINT).
C3	PE1 Bidirectional	Bidirectional	General-purpose digital I/O. Alternate assignments: TXD (USART0).
C4	PF4 Bidirectional	Bidirectional	General-purpose digital I/O. Alternate assignments: TCK (JTAG), ADC4 (ADC).
C5	PF7 Bidirectional	Bidirectional	General-purpose digital I/O. Alternate assignments: TDI (JTAG), ADC7 (ADC).
C6	PK2 Bidirectional	Bidirectional	General-purpose digital I/O. Alternate assignments: PCINT18 (EXINT), ADC10 (ADC).
C7	PK5 Bidirectional	Bidirectional	General-purpose digital I/O. Alternate assignments: PCINT21 (EXINT), ADC13 (ADC).
C8	PJ7 Bidirectional	Bidirectional	General-purpose digital I/O.
C9	PA1 Bidirectional	Bidirectional	General-purpose digital I/O.
C10	PA3 Bidirectional	Bidirectional	General-purpose digital I/O.
D1	PE3 Bidirectional	Bidirectional	General-purpose digital I/O. Alternate assignments: AIN1 (AC), OCA (TC3).
D2	PE4 Bidirectional	Bidirectional	General-purpose digital I/O. Alternate assignments: OCB (TC3), INT4 (EXINT).
D3	PE5 Bidirectional	Bidirectional	General-purpose digital I/O. Alternate assignments: OCC (TC3), INT5 (EXINT).
D4	PE6 Bidirectional	Bidirectional	General-purpose digital I/O. Alternate assignments: T (TC3), INT6 (EXINT).
D5	PH2 Bidirectional	Bidirectional	General-purpose digital I/O. Alternate assignments: XCK (USART2).
D6	PA4 Bidirectional	Bidirectional	General-purpose digital I/O.
D7	PA5 Bidirectional	Bidirectional	General-purpose digital I/O.
D8	PA6 Bidirectional	Bidirectional	General-purpose digital I/O.
D9	PA7 Bidirectional	Bidirectional	General-purpose digital I/O.
D10	PG2 Bidirectional	Bidirectional	General-purpose digital I/O.
E1	PE7 Bidirectional	Bidirectional	General-purpose digital I/O. Alternate assignments: ICP (TC3), INT7 (EXINT), CLKO0 (CPU).
E2	PH0 Bidirectional	Bidirectional	General-purpose digital I/O. Alternate assignments: RXD (USART2).
E3	PH1 Bidirectional	Bidirectional	General-purpose digital I/O. Alternate assignments: TXD (USART2).
E4	PH3 Bidirectional	Bidirectional	General-purpose digital I/O. Alternate assignments: OCA (TC4).
E5	PH5 Bidirectional	Bidirectional	General-purpose digital I/O. Alternate assignments: OCC (TC4).
E6	PJ6 Bidirectional	Bidirectional	General-purpose digital I/O. Alternate assignments: PCINT15 (EXINT).
E7	PJ5 Bidirectional	Bidirectional	General-purpose digital I/O. Alternate assignments: PCINT14 (EXINT).
E8	PJ4 Bidirectional	Bidirectional	General-purpose digital I/O. Alternate assignments: PCINT13 (EXINT).
E9	PJ3 Bidirectional	Bidirectional	General-purpose digital I/O. Alternate assignments: PCINT12 (EXINT).
E10	PJ2 Bidirectional	Bidirectional	General-purpose digital I/O. Alternate assignments: XCK (USART3), PCINT11 (EXINT).
F1	VCC Supply	Supply	Digital supply. Connect every VCC pin and place a local 100 nF ceramic bypass close to each VCC-to-ground pair.
F2	PH4 Bidirectional	Bidirectional	General-purpose digital I/O. Alternate assignments: OCB (TC4).
F3	PH6 Bidirectional	Bidirectional	General-purpose digital I/O. Alternate assignments: OCB (TC2).
F4	PB0 Bidirectional	Bidirectional	General-purpose digital I/O. Alternate assignments: SS (SPI), PCINT0 (EXINT).
F5	PL4 Bidirectional	Bidirectional	General-purpose digital I/O. Alternate assignments: OCB (TC5).
F6	PD1 Bidirectional	Bidirectional	General-purpose digital I/O. Alternate assignments: SDA (TWI), INT1 (EXINT).
F7	PJ1 Bidirectional	Bidirectional	General-purpose digital I/O. Alternate assignments: TXD (USART3), PCINT10 (EXINT).
F8	PJ0 Bidirectional	Bidirectional	General-purpose digital I/O. Alternate assignments: RXD (USART3), PCINT9 (EXINT).
F9	PC7 Bidirectional	Bidirectional	General-purpose digital I/O.
F10	GND Return	Return	Supply return. Connect every ground pin.
G1	GND Return	Return	Supply return. Connect every ground pin.
G2	PB1 Bidirectional	Bidirectional	General-purpose digital I/O. Alternate assignments: SCK (SPI), PCINT1 (EXINT).
G3	PB2 Bidirectional	Bidirectional	General-purpose digital I/O. Alternate assignments: MOSI (SPI), PCINT2 (EXINT).
G4	PB5 Bidirectional	Bidirectional	General-purpose digital I/O. Alternate assignments: OCA (TC1), PCINT5 (EXINT).
G5	PL2 Bidirectional	Bidirectional	General-purpose digital I/O. Alternate assignments: T (TC5).
G6	PD0 Bidirectional	Bidirectional	General-purpose digital I/O. Alternate assignments: SCL (TWI), INT0 (EXINT).
G7	PD5 Bidirectional	Bidirectional	General-purpose digital I/O. Alternate assignments: XCK (USART1).
G8	PC5 Bidirectional	Bidirectional	General-purpose digital I/O.
G9	PC6 Bidirectional	Bidirectional	General-purpose digital I/O.
G10	VCC Supply	Supply	Digital supply. Connect every VCC pin and place a local 100 nF ceramic bypass close to each VCC-to-ground pair.
H1	PB3 Bidirectional	Bidirectional	General-purpose digital I/O. Alternate assignments: MISO (SPI), PCINT3 (EXINT).
H2	PB4 Bidirectional	Bidirectional	General-purpose digital I/O. Alternate assignments: OCA (TC2), PCINT4 (EXINT).
H3	RESET Input	Input	Active-low reset input. The in-system programmer uses this pin to enter serial programming mode.
H4	PL1 Bidirectional	Bidirectional	General-purpose digital I/O. Alternate assignments: ICP (TC5).
H5	PL3 Bidirectional	Bidirectional	General-purpose digital I/O. Alternate assignments: OCA (TC5).
H6	PL7 Bidirectional	Bidirectional	General-purpose digital I/O.
H7	PD4 Bidirectional	Bidirectional	General-purpose digital I/O. Alternate assignments: ICP (TC1).
H8	PC4 Bidirectional	Bidirectional	General-purpose digital I/O.
H9	PC3 Bidirectional	Bidirectional	General-purpose digital I/O.
H10	PC2 Bidirectional	Bidirectional	General-purpose digital I/O.
J1	PH7 Bidirectional	Bidirectional	General-purpose digital I/O.
J2	PG3 Bidirectional	Bidirectional	General-purpose digital I/O. Alternate assignments: TOSC2 (TC2).
J3	PB6 Bidirectional	Bidirectional	General-purpose digital I/O. Alternate assignments: OCB (TC1), PCINT6 (EXINT).
J4	PL0 Bidirectional	Bidirectional	General-purpose digital I/O. Alternate assignments: ICP (TC4).
J5	XTAL2 Output	Output	Oscillator amplifier output. Follow the selected clock mode before attaching a circuit.
J6	PL6 Bidirectional	Bidirectional	General-purpose digital I/O.
J7	PD3 Bidirectional	Bidirectional	General-purpose digital I/O. Alternate assignments: TXD (USART1), INT3 (EXINT).
J8	PC1 Bidirectional	Bidirectional	General-purpose digital I/O.
J9	PC0 Bidirectional	Bidirectional	General-purpose digital I/O.
J10	PG1 Bidirectional	Bidirectional	General-purpose digital I/O.
K1	PB7 Bidirectional	Bidirectional	General-purpose digital I/O. Alternate assignments: OCA (TC0), OCC (TC1), PCINT7 (EXINT).
K2	PG4 Bidirectional	Bidirectional	General-purpose digital I/O. Alternate assignments: TOSC1 (TC2).
K3	VCC Supply	Supply	Digital supply. Connect every VCC pin and place a local 100 nF ceramic bypass close to each VCC-to-ground pair.
K4	GND Return	Return	Supply return. Connect every ground pin.
K5	XTAL1 Input	Input	Oscillator amplifier input or external clock input, depending on clock fuses.
K6	PL5 Bidirectional	Bidirectional	General-purpose digital I/O. Alternate assignments: OCC (TC5).
K7	PD2 Bidirectional	Bidirectional	General-purpose digital I/O. Alternate assignments: RXD (USART1), INT2 (EXINT).
K8	PD6 Bidirectional	Bidirectional	General-purpose digital I/O. Alternate assignments: T (TC1).
K9	PD7 Bidirectional	Bidirectional	General-purpose digital I/O. Alternate assignments: T (TC0).
K10	PG0 Bidirectional	Bidirectional	General-purpose digital I/O.

Signal assignments

Analog comparator

Review each signal assignment and the peripheral enable conditions in the data sheet. AIN0 → PE2 · AIN1 → PE3

USART0 · Serial

Use TXD and RXD for asynchronous serial. XCK is for synchronous mode. The signal levels follow the microcontroller supply domain. TXD → PE1 · RXD → PE0 · XCK → PE2

USART1 · Serial

Use TXD and RXD for asynchronous serial. XCK is for synchronous mode. The signal levels follow the microcontroller supply domain. TXD → PD3 · RXD → PD2 · XCK → PD5

USART2 · Serial

Use TXD and RXD for asynchronous serial. XCK is for synchronous mode. The signal levels follow the microcontroller supply domain. TXD → PH1 · RXD → PH0 · XCK → PH2

USART3 · Serial

Use TXD and RXD for asynchronous serial. XCK is for synchronous mode. The signal levels follow the microcontroller supply domain. TXD → PJ1 · RXD → PJ0 · XCK → PJ2

TWI / I²C

Connect SDA and SCL to the bus with pull-ups to a voltage supported by all devices. Verify the pull-up value for the bus capacitance and rate. SDA → PD1 · SCL → PD0

SPI peripheral

Use SCK, MOSI, MISO and a chip-select line. Firmware selects direction and clock phase. Check the separate ISP mapping when programming. SS → PB0 · MOSI → PB2 · MISO → PB3 · SCK → PB1

Timer/Counter 0

Review each signal assignment and the peripheral enable conditions in the data sheet. T → PD7 · OCB → PG5 · OCA → PB7

Timer/Counter 2

Review each signal assignment and the peripheral enable conditions in the data sheet. TOSC1 → PG4 · TOSC2 → PG3 · OCA → PB4 · OCB → PH6

Timer/Counter 5

Review each signal assignment and the peripheral enable conditions in the data sheet. T → PL2 · ICP → PL1 · OCA → PL3 · OCB → PL4 · OCC → PL5

Timer/Counter 4

Review each signal assignment and the peripheral enable conditions in the data sheet. ICP → PL0 · OCA → PH3 · OCB → PH4 · OCC → PH5

Timer/Counter 3

Review each signal assignment and the peripheral enable conditions in the data sheet. T → PE6 · ICP → PE7 · OCA → PE3 · OCB → PE4 · OCC → PE5

Timer/Counter 1

Review each signal assignment and the peripheral enable conditions in the data sheet. T → PD6 · ICP → PD4 · OCA → PB5 · OCB → PB6 · OCC → PB7

JTAG

Check the JTAG fuse and enable state before using the pins for GPIO. JTAG uses TCK, TMS, TDI and TDO. TCK → PF4 · TMS → PF5 · TDO → PF6 · TDI → PF7

External interrupts

Review each signal assignment and the peripheral enable conditions in the data sheet. PCINT0 → PB0 · PCINT1 → PB1 · PCINT2 → PB2 · PCINT3 → PB3 · PCINT4 → PB4 · PCINT5 → PB5 · PCINT6 → PB6 · PCINT7 → PB7 · PCINT8 → PE0 · PCINT9 → PJ0 · PCINT10 → PJ1 · PCINT11 → PJ2 · PCINT12 → PJ3 · PCINT13 → PJ4 · PCINT14 → PJ5 · PCINT15 → PJ6 · PCINT16 → PK0 · PCINT17 → PK1 · PCINT18 → PK2 · PCINT19 → PK3 · PCINT20 → PK4 · PCINT21 → PK5 · PCINT22 → PK6 · PCINT23 → PK7 · INT0 → PD0 · INT1 → PD1 · INT2 → PD2 · INT3 → PD3 · INT4 → PE4 · INT5 → PE5 · INT6 → PE6 · INT7 → PE7

System clock

Review each signal assignment and the peripheral enable conditions in the data sheet. CLKO0 → PE7

PE7 (E1)

Analog-to-digital converter

Select the analog channel and reference in firmware. The reference choice and supply constrain the input range. ADC0 → PF0 · ADC1 → PF1 · ADC2 → PF2 · ADC3 → PF3 · ADC4 → PF4 · ADC5 → PF5 · ADC6 → PF6 · ADC7 → PF7 · ADC8 → PK0 · ADC9 → PK1 · ADC10 → PK2 · ADC11 → PK3 · ADC12 → PK4 · ADC13 → PK5 · ADC14 → PK6 · ADC15 → PK7

Electrical limits

Parameter	Limit	Conditions and source
Program flash256 KiB	256 KiB	Nonvolatile program memory. 2549Q · Memory
SRAM8 KiB	8 KiB	Volatile data and stack storage. 2549Q · Memory
EEPROM4 KiB	4 KiB	Nonvolatile data storage. 2549Q · Memory
Clock and supplyOrder-code dependent	Order-code dependent	Use the grade table and the device’s speed-versus-voltage curve. 2549Q · Electrical Characteristics

Models and documents

Each package lists the documented order codes and variants covered by this map. Select the marked model to see its peripheral assignments and memory. Check the exact order code and datasheet revision before laying out a PCB.

ATmega2560: 256 KiB flash · 8 KiB SRAM · 4 KiB EEPROM. Choose the marked order code for voltage, clock, and temperature.
ATmega2560V-8CU: 256 KiB flash · 8 KiB SRAM · 4 KiB EEPROM · 1.8–5.5 V · 8 MHz maximum · -40 to +85 °C
ATmega2560V-8CUR: 256 KiB flash · 8 KiB SRAM · 4 KiB EEPROM · 1.8–5.5 V · 8 MHz maximum · -40 to +85 °C
ATmega2560-16CU: 256 KiB flash · 8 KiB SRAM · 4 KiB EEPROM · 4.5–5.5 V · 16 MHz maximum · -40 to +85 °C
ATmega2560-16CUR: 256 KiB flash · 8 KiB SRAM · 4 KiB EEPROM · 4.5–5.5 V · 16 MHz maximum · -40 to +85 °C

ATmega2560 data sheet· 2549Q · Pin configuration, electrical characteristics, ordering table and serial programming.
ATmega_DFP Device Family Pack· Machine-readable device definition: package contacts, peripheral routes, and memory sizes.
AVR Microcontroller Hardware Design Considerations· Power supply, reset network, and programmer connection guidance.
ATmega2560 documentation and errata· Check current manufacturer documentation, ordering status and silicon revision applicability.
AVR source register· Source identifiers, applicability, retrieval dates, and SHA-256 digests.