Definitions of the interrupt vectors.
The interrupt vectors related codes are defined in hardware/tools/avr/avr/include/avr/iom328p.h as below.
/* Interrupt Vectors */ /* Interrupt Vector 0 is the reset vector. */ #define INT0_vect _VECTOR(1) /* External Interrupt Request 0 */ #define INT1_vect _VECTOR(2) /* External Interrupt Request 1 */ #define PCINT0_vect _VECTOR(3) /* Pin Change Interrupt Request 0 */ #define PCINT1_vect _VECTOR(4) /* Pin Change Interrupt Request 0 */ #define PCINT2_vect _VECTOR(5) /* Pin Change Interrupt Request 1 */ #define WDT_vect _VECTOR(6) /* Watchdog Time-out Interrupt */ #define TIMER2_COMPA_vect _VECTOR(7) /* Timer/Counter2 Compare Match A */ #define TIMER2_COMPB_vect _VECTOR(8) /* Timer/Counter2 Compare Match A */ #define TIMER2_OVF_vect _VECTOR(9) /* Timer/Counter2 Overflow */ #define TIMER1_CAPT_vect _VECTOR(10) /* Timer/Counter1 Capture Event */ #define TIMER1_COMPA_vect _VECTOR(11) /* Timer/Counter1 Compare Match A */ #define TIMER1_COMPB_vect _VECTOR(12) /* Timer/Counter1 Compare Match B */ #define TIMER1_OVF_vect _VECTOR(13) /* Timer/Counter1 Overflow */ #define TIMER0_COMPA_vect _VECTOR(14) /* TimerCounter0 Compare Match A */ #define TIMER0_COMPB_vect _VECTOR(15) /* TimerCounter0 Compare Match B */ #define TIMER0_OVF_vect _VECTOR(16) /* Timer/Couner0 Overflow */ #define SPI_STC_vect _VECTOR(17) /* SPI Serial Transfer Complete */ #define USART_RX_vect _VECTOR(18) /* USART Rx Complete */ #define USART_UDRE_vect _VECTOR(19) /* USART, Data Register Empty */ #define USART_TX_vect _VECTOR(20) /* USART Tx Complete */ #define ADC_vect _VECTOR(21) /* ADC Conversion Complete */ #define EE_READY_vect _VECTOR(22) /* EEPROM Ready */ #define ANALOG_COMP_vect _VECTOR(23) /* Analog Comparator */ #define TWI_vect _VECTOR(24) /* Two-wire Serial Interface */ #define SPM_READY_vect _VECTOR(25) /* Store Program Memory Read */ #define _VECTORS_SIZE (26 * 4)
They call _VECTOR().