The MSP432™ uses a additional level for interrupts: the Nested Vectored Interrupt Controller (NVIC). Every interrupt you request must be enabled in the NVIC.

To enable for example the Timer_A0_N interrupt you have to call also the NVIC function:

NVIC_EnableIRQ(TA0_N_IRQn);

You can see a list of all interrupts in the msp432p401r.h file, there is a enum type IRQn_Type.

At next you can choose between Code based and RAM based interrupt vectors.

Code based interrupt

The Code based interrupts are hardlinked between the IVT and the ISR.

To put a ISR in the IVT you have define the ISR in your application first:

// ISR for Timer_A0_N
void Timer_A0_N (void)
{
	// handle IRQ
}

At default the IVT is defined in the msp432_startup_ccs.c file, there you have to declare your function:

/* External declarations for the interrupt handlers used by the application. */
/* To be added by user */
extern void Timer_A0_N (void);

At last you assign the function to the IVT:

#pragma DATA_SECTION(interruptVectors, ".intvecs")
void (* const interruptVectors[])(void) =
{
	(void (*)(void))((uint32_t)&__STACK_END),
	...
	Timer_A0_N,                             /* TA0_N ISR                 */
	...
};

In the document SLAA656 (MSP432™ Platform Porting Guide) version 2015-03 is witten the old „#pragma vector“ method should also work, but at my tests the compiler thows some errors on it.

RAM based interrupt

RAM based interrupts can be used in oder if you have multiple applications running on your MSP and every application has it’s own ISRs.

For the use of RAM based interrupts I recommend to use the MSP432 DriverLib Interrupt API. You have to create a RAM table and manage the IV entrys and the API is straight forward and implements all the needed functions.

You can start using Code based interrupts, if you call the Interrupt_registerInterrupt function at first time, it will copy the whole IVT from Code to RAM.

The Interrupt_registerInterrupt and Interrupt_unregisterInterrupt does not enable or disable the interrupt, you have to call Interrupt_enableInterrupt and Interrupt_disableInterrupt manually.

As example the timer interrupt:

// from MSP432 DriverLib
#include "interrupt.h"
 
// ISR for Timer_A0_N
void Timer_A0_N (void)
{
	// handle IRQ
}
 
void main(void)
{
	...
	Interrupt_registerInterrupt(INT_TA0_N, Timer_A0_N);
	Interrupt_enableInterrupt(INT_TA0_N);
	...
}