Lpc2000

---- Original Message ----
From: "mhaines4102" <mhaines4102@...>
To: <lpc2000@yahoogroups.com>
Sent: Thursday, November 10, 2005 9:40 PM
Subject: [lpc2000] Timer Interrupt on Crossworks

> I have a dumb question. I am embarrassed to ask but... I am using a
> timer interrupt. My setup is as follows:
> /* Timer 0 interrupt is an IRQ interrupt */
> VICIntSelect &= ~(0x10);
> /* Enable timer 0 interrupt */
> VICIntEnable = (0x10);
> /* Use slot 0 for timer 0 interrupt */
> VICVectCntl0 = 0x24;
> /* Set the address of ISR for slot 0 */
> VICVectAddr0 = (unsigned long)timer0ISR;
> /* Reset timer 0 */
> T0TCR = 0;
> /* Set the timer 0 prescale counter */
> T0PR = 2500;
> /* Set timer 0 match register */
> T0MR0 = 1000;
> /* Generate interrupt and reset counter on match */
> T0MCR = 3;
> /* Start timer 0 */
> T0TCR = 0x01;
> T0IR = 0xFF;
> 
> The interrupt was being called, then it stopped. I changed some
> settings and it came back, then it stopped again. I added T0IR = 0xFF;
> to the end of the setup and it worked, then it stopped again. What
> have I missed? I am beginning to feel like a goof.

Have you remembered a
   VICVectAddr = 0x00;  /* Clear interrupt flag in the VIC */
and a
   T0IR = 0x01  /* Clear the match 0 interrupt flag */
in your interrupt handler?

Karl Olsen