Program is not leaving the ISR (timer0 mat0 interrupt)

lpcware — Thu, 16 Jun 2016 02:19:19 GMT

Content originally posted in LPCWare by emielzij on Wed Dec 17 09:03:21 MST 2014
I have an external clock source that drives the counter0 of the LPC11C24.
If the counter value matches the match register 0 (in the code forced to a value 10 for testing purposes) then the counter should reset to 0 and the code should jump to an isr.

Here is my code:

#define timer0match 10//0-65535

#include "LPC11xx.h"

void timer0init(void)
{
LPC_IOCON->PIO0_2 |= (1 << 1);//Selects function CT16B0_CAP0
LPC_SYSCON->SYSAHBCLKCTRL |= (1 << 7);//Enable clock for 16-bit counter/timer0
LPC_TMR16B0->CTCR |= (1 << 0);//TC incremented on rising edge CAP input (Selected)

//CAP0 as clock source, default CAP0

//Configure CT16B0_MAT0 (PIO0_8) as match function for external measurements
LPC_GPIO0->DIR |= (1 << 8);        //Set PIO0_8 as output
LPC_TMR16B0->EMR|= 0x00000030;//EMC0, Toggle the corresponding External Match bit/output
LPC_IOCON->PIO0_8|= (1 << 1);        //Selects function CT16B0_MAT0

LPC_TMR16B0->MR0 = timer0match;//Set match value
LPC_TMR16B0->MCR|= (1 << 0);        //Interrupt if TC==MR0
LPC_TMR16B0->MCR|= (1 << 1);       //Reset TC to 0 if TC==MR0

LPC_TMR16B0->TCR |= (1 << 0);//Enable timer 0

//Reset timer 0
LPC_TMR16B0->TCR |= (1 << 1);
LPC_TMR16B0->TCR &= ~(1 << 1);

NVIC_EnableIRQ(TIMER_16_0_IRQn);
}

int main(void)
{
int i=0;

    LPC_SYSCON->SYSAHBCLKCTRL   |= (1<<6);//GPIO CLOCK ENABLE
    LPC_SYSCON->SYSAHBCLKCTRL   |= (1<<16);//Enable IOCON

    LPC_GPIO0->DIR|= (1 << 3);//OUTPUT
    LPC_IOCON->PIO0_3&= ~(1 << 3);        //Disable pull up

    timer0init();

    while(1)
    {
    LPC_GPIO0->DATA|= (1 << 3);
    for(i=0; i<100; i++);
    LPC_GPIO0->DATA &= ~(1 << 3); //toggle pin
    for(i=0; i<100; i++);

    }
    return 0 ;
}

void TIMER_16_0_IRQHandler(void)
{
LPC_TMR16B0->IR |= (1 << 0);//Clear interrupt flag by writing a 1
}

The PIO0_3 is not toggled in the while(1) loop, the program get stuck in the ISR I think. If I remove NVIC_EnableIRQ(TIMER_16_0_IRQn); from the code, the program runs fine. The hardware interrupt, toggle a pin at a match works fine in both cases.

Am I doing something wrong with the interrupt clearing?

Re: Program is not leaving the ISR (timer0 mat0 interrupt)

lpcware — Thu, 16 Jun 2016 02:19:20 GMT

Content originally posted in LPCWare by R2D2 on Wed Dec 17 10:18:10 MST 2014

Quote: emielzij
...the program get stuck in the ISR I think.

:quest:

And what's the debugger telling you?

Probably your ISR name is wrong :((

void TIMER[color=#f00]_[/color]16_0_IRQHandler(void)

Re: Program is not leaving the ISR (timer0 mat0 interrupt)

lpcware — Thu, 16 Jun 2016 02:19:20 GMT

Content originally posted in LPCWare by emielzij on Wed Dec 17 14:38:45 MST 2014
Indeed, the ISR name was incorrect.
Thank you

topic Program is not leaving the ISR (timer0 mat0 interrupt) in LPCXpresso IDE

Program is not leaving the ISR (timer0 mat0 interrupt)

Re: Program is not leaving the ISR (timer0 mat0 interrupt)

Re: Program is not leaving the ISR (timer0 mat0 interrupt)