The interrupt vector table

The interrupt vector table, often abbreviated to IVT or simply IV, is an array of pointers to functions associated by the CPU to handle specific exceptions, such as faults, system service requests from the application, and interrupt requests from peripherals. The IVT is usually located at the beginning of the binary image and thus is stored starting from the lowest address in the flash memory.

An interrupt request from a hardware component or peripheral will force the CPU to abruptly suspend the execution and execute the function at the associated position in the vector. For this reason, these functions are called interrupt service routines (or simply ISRs). Runtime exceptions and faults can be handled in the same way as hardware interrupts, so special service routines are associated with internal CPU triggers through the same table.

The order of the ISRs enumerated in the vector, and their exact positions depend on the CPU architecture, the microcontroller...