Before enabling interrupts define and register your interrupt service routine (ISR) functions. First write ISR function as you would do for any other functions
void myisr_for_group1(void) {
/* do something */
}
Then register this function
intc_register_isrhandler(&myisr_for_group1, 1, 0);
Here the first parameter is a function pointer to your myisr_for_group1() function. The second parameter defines the which interrupt group calls this function and the last one tells the priority level.
Hint
Refer Table 12-3 (Interrupt Request Signal Map) in datasheet page 41 to see what peripheral belongs to which group. For example, RTC belongs to group 1.
When all the ISR functions have been declared it is time to initialize interrupts. Use the following init function to do all the magic
intc_init();
After initialization you can enable and disable interrupts globally by using these functions
intc_enable_globally();
intc_disable_globally();