SparkFun Forums 

Where electronics enthusiasts find answers.

Everything ARM and LPC
By lpc1769
Hi all,

I am using LPC1769.

What i would like to achieve is that, every 40 ms, i would like to have auto interrupt and print out a message.

I have searched and found out that it can be achieved using Repetitive Interrupt Timer to generate interrupts at specified time intervals.

I have understood meanings of 4 registers associated with RI (such as ICOMPVAL, RIMASK, RICTRL, RICOUNTER).

Once i run my code, i encountered hard fault. Can kindly check for me where i went wrong. Thank you.
Code: Select all

#include "stdio.h"
#include "LPC17xx.h"

// EINT3 Interrupt Handler
void RIT_IRQHandler(void)
		printf("Repetitive interrupt every 40 ms\n");

	// Clear RI Control register Interrupt
	LPC_RIT->RICTRL |= 1<<0; //bit 0 = 1 => write 0 to value 1 will clear the interrupt flag


int main (void)
	//RI compare value register -> Compare value to get 40 ms, cpu speed is 120 000 000
	LPC_RIT->RICOMPVAL |= 0x493E00; //OR operation so that existing values will not be effected

	//RI mask register -> RI masking to compare with counter
	LPC_RIT->RIMASK |= 0x493E00;

	//RI control register
	LPC_RIT->RICTRL |= 1<<1; //bit 1 = 1 => The timer will be cleared to 0 whenever the counter value equals RICOMPVAL
	LPC_RIT->RICTRL |= 1<<3; //bit 3 = 1 => Timer enable

	// Enable RI TINT interrupt


By lpc1769
fll-freak wrote:Why/how did this get marked as solved without a single reply or an edit for the OP? It would be nice to leave an explanation for the next person that comes along with a similar question.
hi fll-freak,

My apology, it was click solved unoticed. In fact, problem haven't solved yet. Thanks for pointing it out.
By Tanner
Ok, I hope for your sake you've gotten this to work by now. In case you haven't and for the sake of the next person that sees this page:

You have to power the RIT subsystem in the PCONP register. If you include:

PCONP |= (1<<16);

You should be able to use the RIT subsystem. Good luck!
long long title how many chars? lets see 123 ok more? yes 60

We have created lots of YouTube videos just so you can achieve [...]

Another post test yes yes yes or no, maybe ni? :-/

The best flat phpBB theme around. Period. Fine craftmanship and [...]

Do you need a super MOD? Well here it is. chew on this

All you need is right here. Content tag, SEO, listing, Pizza and spaghetti [...]

Lasagna on me this time ok? I got plenty of cash

this should be fantastic. but what about links,images, bbcodes etc etc? [...]