ATmega16U4 interrupt vectors

The 43 vectors at the start of flash, two words each (a JMP). A lower number has the higher priority; vector 0 is reset. In avr-gcc a handler is ISR(NAME_vect).

Vector	Program address	Name	Handler	Source
0	`0x0000`	RESET	reset: `main()` after start-up	External Pin,Power-on Reset,Brown-out Reset,Watchdog Reset,and JTAG AVR Reset. See Datasheet.
1	`0x0002`	INT0	`INT0_vect`	External Interrupt Request 0
2	`0x0004`	INT1	`INT1_vect`	External Interrupt Request 1
3	`0x0006`	INT2	`INT2_vect`	External Interrupt Request 2
4	`0x0008`	INT3	`INT3_vect`	External Interrupt Request 3
5	`0x000A`	RESERVED1	`RESERVED1_vect`	Reserved1
6	`0x000C`	RESERVED2	`RESERVED2_vect`	Reserved2
7	`0x000E`	INT6	`INT6_vect`	External Interrupt Request 6
8	`0x0010`	RESERVED3	`RESERVED3_vect`	Reserved3
9	`0x0012`	PCINT0	`PCINT0_vect`	Pin Change Interrupt Request 0
10	`0x0014`	USB_GEN	`USB_GEN_vect`	USB General Interrupt Request
11	`0x0016`	USB_COM	`USB_COM_vect`	USB Endpoint/Pipe Interrupt Communication Request
12	`0x0018`	WDT	`WDT_vect`	Watchdog Time-out Interrupt
13	`0x001A`	RESERVED4	`RESERVED4_vect`	Reserved4
14	`0x001C`	RESERVED5	`RESERVED5_vect`	Reserved5
15	`0x001E`	RESERVED6	`RESERVED6_vect`	Reserved6
16	`0x0020`	TIMER1_CAPT	`TIMER1_CAPT_vect`	Timer/Counter1 Capture Event
17	`0x0022`	TIMER1_COMPA	`TIMER1_COMPA_vect`	Timer/Counter1 Compare Match A
18	`0x0024`	TIMER1_COMPB	`TIMER1_COMPB_vect`	Timer/Counter1 Compare Match B
19	`0x0026`	TIMER1_COMPC	`TIMER1_COMPC_vect`	Timer/Counter1 Compare Match C
20	`0x0028`	TIMER1_OVF	`TIMER1_OVF_vect`	Timer/Counter1 Overflow
21	`0x002A`	TIMER0_COMPA	`TIMER0_COMPA_vect`	Timer/Counter0 Compare Match A
22	`0x002C`	TIMER0_COMPB	`TIMER0_COMPB_vect`	Timer/Counter0 Compare Match B
23	`0x002E`	TIMER0_OVF	`TIMER0_OVF_vect`	Timer/Counter0 Overflow
24	`0x0030`	SPI_STC	`SPI_STC_vect`	SPI Serial Transfer Complete
25	`0x0032`	USART1_RX	`USART1_RX_vect`	USART1, Rx Complete
26	`0x0034`	USART1_UDRE	`USART1_UDRE_vect`	USART1 Data register Empty
27	`0x0036`	USART1_TX	`USART1_TX_vect`	USART1, Tx Complete
28	`0x0038`	ANALOG_COMP	`ANALOG_COMP_vect`	Analog Comparator
29	`0x003A`	ADC	`ADC_vect`	ADC Conversion Complete
30	`0x003C`	EE_READY	`EE_READY_vect`	EEPROM Ready
31	`0x003E`	TIMER3_CAPT	`TIMER3_CAPT_vect`	Timer/Counter3 Capture Event
32	`0x0040`	TIMER3_COMPA	`TIMER3_COMPA_vect`	Timer/Counter3 Compare Match A
33	`0x0042`	TIMER3_COMPB	`TIMER3_COMPB_vect`	Timer/Counter3 Compare Match B
34	`0x0044`	TIMER3_COMPC	`TIMER3_COMPC_vect`	Timer/Counter3 Compare Match C
35	`0x0046`	TIMER3_OVF	`TIMER3_OVF_vect`	Timer/Counter3 Overflow
36	`0x0048`	TWI	`TWI_vect`	2-wire Serial Interface
37	`0x004A`	SPM_READY	`SPM_READY_vect`	Store Program Memory Read
38	`0x004C`	TIMER4_COMPA	`TIMER4_COMPA_vect`	Timer/Counter4 Compare Match A
39	`0x004E`	TIMER4_COMPB	`TIMER4_COMPB_vect`	Timer/Counter4 Compare Match B
40	`0x0050`	TIMER4_COMPD	`TIMER4_COMPD_vect`	Timer/Counter4 Compare Match D
41	`0x0052`	TIMER4_OVF	`TIMER4_OVF_vect`	Timer/Counter4 Overflow
42	`0x0054`	TIMER4_FPF	`TIMER4_FPF_vect`	Timer/Counter4 Fault Protection Interrupt