Can anyone tell me why my interrupt is not firing? The T0IR flag is
set upon rollover of the TIMER0 32 bit timer, but my code is not
vectored to the interrupt code. My variable 'system_timer' never
gets
decremented.
unsigned long system_timer, j;
void decrement_timers() __irq
{
// occurs 896 times per second
system_timer--;
T0IR |= 1;
}
int main()
{
VPBDIV = 1;
// set up delay timer (TIMER 0)
VICIntSelect = 0; // all interrupts classified as IRQs
VICVectCntl0 = 0x00000024;
VICVectAddr0 = (unsigned int) decrement_timers;
VICIntEnable = 0x00000010;
// Disable Timer0 and Reset Interrupt Flag
T0TCR = 0;
T0IR |= 1;
T0MR0 = 0;
T0MCR = 1;
T0CTCR = 0;
T0PR = 0;
T0TCR = 1;
// just an infinite loop to check Timer0
system_timer = 4000;
j = 0;
for(;;)
{
j = j + 2;
}
LPC2138 Timer0 Interrupt
Started by ●December 8, 2005
Reply by ●December 8, 20052005-12-08
Maybe interrupts are not enabled?
--- In lpc2000@lpc2..., "dodge1955" <sutton@h...> wrote:
>
> Can anyone tell me why my interrupt is not firing? The T0IR flag is
> set upon rollover of the TIMER0 32 bit timer, but my code is not
> vectored to the interrupt code. My variable 'system_timer' never
gets
> decremented.
>
> unsigned long system_timer, j;
>
> void decrement_timers() __irq
> {
> // occurs 896 times per second
>
> system_timer--;
>
> T0IR |= 1;
> }
>
> int main()
> {
> VPBDIV = 1;
>
> // set up delay timer (TIMER 0)
>
> VICIntSelect = 0; // all interrupts classified as IRQs
> VICVectCntl0 = 0x00000024;
> VICVectAddr0 = (unsigned int) decrement_timers;
> VICIntEnable = 0x00000010;
>
> // Disable Timer0 and Reset Interrupt Flag
>
> T0TCR = 0;
> T0IR |= 1;
>
> T0MR0 = 0;
> T0MCR = 1;
>
> T0CTCR = 0;
> T0PR = 0;
> T0TCR = 1;
>
> // just an infinite loop to check Timer0
>
> system_timer = 4000;
>
> j = 0;
> for(;;)
> {
> j = j + 2;
> }
>
--- In lpc2000@lpc2..., "dodge1955" <sutton@h...> wrote:
>
> Can anyone tell me why my interrupt is not firing? The T0IR flag is
> set upon rollover of the TIMER0 32 bit timer, but my code is not
> vectored to the interrupt code. My variable 'system_timer' never
gets
> decremented.
>
> unsigned long system_timer, j;
>
> void decrement_timers() __irq
> {
> // occurs 896 times per second
>
> system_timer--;
>
> T0IR |= 1;
> }
>
> int main()
> {
> VPBDIV = 1;
>
> // set up delay timer (TIMER 0)
>
> VICIntSelect = 0; // all interrupts classified as IRQs
> VICVectCntl0 = 0x00000024;
> VICVectAddr0 = (unsigned int) decrement_timers;
> VICIntEnable = 0x00000010;
>
> // Disable Timer0 and Reset Interrupt Flag
>
> T0TCR = 0;
> T0IR |= 1;
>
> T0MR0 = 0;
> T0MCR = 1;
>
> T0CTCR = 0;
> T0PR = 0;
> T0TCR = 1;
>
> // just an infinite loop to check Timer0
>
> system_timer = 4000;
>
> j = 0;
> for(;;)
> {
> j = j + 2;
> }
>
Reply by ●December 8, 20052005-12-08
Make sure your global IRQ flag is clear, (I_BIT in CPSR needs to be
0). Also you need to clear the VICVectAddr (VICVectAddr = 0x00000000)
at the end of your interrupt.
Other then that it should work, however if wont occur 896 times per
second, more like once every 71s with a 60Mhz PCLK.
Mark
--- In lpc2000@lpc2..., "dodge1955" <sutton@h...> wrote:
>
> Can anyone tell me why my interrupt is not firing? The T0IR flag is
> set upon rollover of the TIMER0 32 bit timer, but my code is not
> vectored to the interrupt code. My variable 'system_timer' never gets
> decremented.
>
> unsigned long system_timer, j;
>
> void decrement_timers() __irq
> {
> // occurs 896 times per second
>
> system_timer--;
>
> T0IR |= 1;
> }
>
> int main()
> {
> VPBDIV = 1;
>
> // set up delay timer (TIMER 0)
>
> VICIntSelect = 0; // all interrupts classified as IRQs
> VICVectCntl0 = 0x00000024;
> VICVectAddr0 = (unsigned int) decrement_timers;
> VICIntEnable = 0x00000010;
>
> // Disable Timer0 and Reset Interrupt Flag
>
> T0TCR = 0;
> T0IR |= 1;
>
> T0MR0 = 0;
> T0MCR = 1;
>
> T0CTCR = 0;
> T0PR = 0;
> T0TCR = 1;
>
> // just an infinite loop to check Timer0
>
> system_timer = 4000;
>
> j = 0;
> for(;;)
> {
> j = j + 2;
> }
>
0). Also you need to clear the VICVectAddr (VICVectAddr = 0x00000000)
at the end of your interrupt.
Other then that it should work, however if wont occur 896 times per
second, more like once every 71s with a 60Mhz PCLK.
Mark
--- In lpc2000@lpc2..., "dodge1955" <sutton@h...> wrote:
>
> Can anyone tell me why my interrupt is not firing? The T0IR flag is
> set upon rollover of the TIMER0 32 bit timer, but my code is not
> vectored to the interrupt code. My variable 'system_timer' never gets
> decremented.
>
> unsigned long system_timer, j;
>
> void decrement_timers() __irq
> {
> // occurs 896 times per second
>
> system_timer--;
>
> T0IR |= 1;
> }
>
> int main()
> {
> VPBDIV = 1;
>
> // set up delay timer (TIMER 0)
>
> VICIntSelect = 0; // all interrupts classified as IRQs
> VICVectCntl0 = 0x00000024;
> VICVectAddr0 = (unsigned int) decrement_timers;
> VICIntEnable = 0x00000010;
>
> // Disable Timer0 and Reset Interrupt Flag
>
> T0TCR = 0;
> T0IR |= 1;
>
> T0MR0 = 0;
> T0MCR = 1;
>
> T0CTCR = 0;
> T0PR = 0;
> T0TCR = 1;
>
> // just an infinite loop to check Timer0
>
> system_timer = 4000;
>
> j = 0;
> for(;;)
> {
> j = j + 2;
> }
>
Reply by ●December 8, 20052005-12-08
Maybe you forgot to enable global interrupt just before entering the loop?
// just an infinite loop to check Timer0
system_timer = 4000;
__ARMLIB_enableIRQ(); j = 0;
for(;;)
{
j = j + 2;
} /jd
_____
Fra: lpc2000@lpc2... [mailto:lpc2000@lpc2...] Pvegne af
dodge1955
Sendt: 8. december 2005 17:51
Til: lpc2000@lpc2...
Emne: [lpc2000] LPC2138 Timer0 Interrupt
Can anyone tell me why my interrupt is not firing? The T0IR flag is
set upon rollover of the TIMER0 32 bit timer, but my code is not
vectored to the interrupt code. My variable 'system_timer' never gets
decremented.
unsigned long system_timer, j;
void decrement_timers() __irq
{
// occurs 896 times per second
system_timer--;
T0IR |= 1;
}
int main()
{
VPBDIV = 1;
// set up delay timer (TIMER 0)
VICIntSelect = 0; // all interrupts classified as IRQs
VICVectCntl0 = 0x00000024;
VICVectAddr0 = (unsigned int) decrement_timers;
VICIntEnable = 0x00000010;
// Disable Timer0 and Reset Interrupt Flag
T0TCR = 0;
T0IR |= 1;
T0MR0 = 0;
T0MCR = 1;
T0CTCR = 0;
T0PR = 0;
T0TCR = 1;
// just an infinite loop to check Timer0
system_timer = 4000;
j = 0;
for(;;)
{
j = j + 2;
}
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_____
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_____
// just an infinite loop to check Timer0
system_timer = 4000;
__ARMLIB_enableIRQ(); j = 0;
for(;;)
{
j = j + 2;
} /jd
_____
Fra: lpc2000@lpc2... [mailto:lpc2000@lpc2...] Pvegne af
dodge1955
Sendt: 8. december 2005 17:51
Til: lpc2000@lpc2...
Emne: [lpc2000] LPC2138 Timer0 Interrupt
Can anyone tell me why my interrupt is not firing? The T0IR flag is
set upon rollover of the TIMER0 32 bit timer, but my code is not
vectored to the interrupt code. My variable 'system_timer' never gets
decremented.
unsigned long system_timer, j;
void decrement_timers() __irq
{
// occurs 896 times per second
system_timer--;
T0IR |= 1;
}
int main()
{
VPBDIV = 1;
// set up delay timer (TIMER 0)
VICIntSelect = 0; // all interrupts classified as IRQs
VICVectCntl0 = 0x00000024;
VICVectAddr0 = (unsigned int) decrement_timers;
VICIntEnable = 0x00000010;
// Disable Timer0 and Reset Interrupt Flag
T0TCR = 0;
T0IR |= 1;
T0MR0 = 0;
T0MCR = 1;
T0CTCR = 0;
T0PR = 0;
T0TCR = 1;
// just an infinite loop to check Timer0
system_timer = 4000;
j = 0;
for(;;)
{
j = j + 2;
}
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<http://groups.yahoo.com/gads?t=ms&k=Microprocessor&w1=Microprocessor&w2=Mic
rocontrollers&w3=Pic+microcontrollers&w451+microprocessor&c=4&s&.sig=t
sVC-J9hJ5qyXg0WPR0l6g>
Microcontrollers
<http://groups.yahoo.com/gads?t=ms&k=Microcontrollers&w1=Microprocessor&w2=M
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w2=Microcontrollers&w3=Pic+microcontrollers&w451+microprocessor&c=4&s&
.sig=TpkoX4KofDJ7c6LyBvUqVQ> microcontrollers 8051
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_____
> Terms of Service.
_____
Reply by ●December 8, 20052005-12-08
First of all; you are not acknowledging your VIC interrupt. This will
cause your system to 'look' like it is not interrupting.
void decrement_timers() __irq
{
// occurs 896 times per second
system_timer--;
T0IR = 1;
VICVectAddr = 0; /* <--- Acknowledge VIC Interrupt !!! */
}
plus: Here is a snippet from an initialization routine that I use, and
it works perfectly:
extern unsigned long acquireFOSC(void); // VPB clock in Hertz
void Timer0_init (const unsigned vicSlot)
{
/*** some sundry global variable initializations here ***/
...
...
...
/*** now initialize the timer and install the service ***/
T0PR = (acquireFOSC () / 2000) - 1;/* Prescaler ~ .0005 sec */
T0MR0 = 1; /* Set MR0 count = .001 sec */
T0MCR = 0x03; /* Set to reset & interrupt */
VIC_install (vicSlot,VICCH_TMR0,TMR0_isr); //install the service
T0TCR = 1; /* Timer0 Enable */
}
--- In lpc2000@lpc2..., "dodge1955" <sutton@h...> wrote:
>
> Can anyone tell me why my interrupt is not firing? The T0IR flag is
> set upon rollover of the TIMER0 32 bit timer, but my code is not
> vectored to the interrupt code. My variable 'system_timer' never
gets
> decremented.
>
> unsigned long system_timer, j;
>
> void decrement_timers() __irq
> {
> // occurs 896 times per second
>
> system_timer--;
>
> T0IR |= 1;
> }
>
> int main()
> {
> VPBDIV = 1;
>
> // set up delay timer (TIMER 0)
>
> VICIntSelect = 0; // all interrupts classified as IRQs
> VICVectCntl0 = 0x00000024;
> VICVectAddr0 = (unsigned int) decrement_timers;
> VICIntEnable = 0x00000010;
>
> // Disable Timer0 and Reset Interrupt Flag
>
> T0TCR = 0;
> T0IR |= 1;
>
> T0MR0 = 0;
> T0MCR = 1;
>
> T0CTCR = 0;
> T0PR = 0;
> T0TCR = 1;
>
> // just an infinite loop to check Timer0
>
> system_timer = 4000;
>
> j = 0;
> for(;;)
> {
> j = j + 2;
> }
>
cause your system to 'look' like it is not interrupting.
void decrement_timers() __irq
{
// occurs 896 times per second
system_timer--;
T0IR = 1;
VICVectAddr = 0; /* <--- Acknowledge VIC Interrupt !!! */
}
plus: Here is a snippet from an initialization routine that I use, and
it works perfectly:
extern unsigned long acquireFOSC(void); // VPB clock in Hertz
void Timer0_init (const unsigned vicSlot)
{
/*** some sundry global variable initializations here ***/
...
...
...
/*** now initialize the timer and install the service ***/
T0PR = (acquireFOSC () / 2000) - 1;/* Prescaler ~ .0005 sec */
T0MR0 = 1; /* Set MR0 count = .001 sec */
T0MCR = 0x03; /* Set to reset & interrupt */
VIC_install (vicSlot,VICCH_TMR0,TMR0_isr); //install the service
T0TCR = 1; /* Timer0 Enable */
}
--- In lpc2000@lpc2..., "dodge1955" <sutton@h...> wrote:
>
> Can anyone tell me why my interrupt is not firing? The T0IR flag is
> set upon rollover of the TIMER0 32 bit timer, but my code is not
> vectored to the interrupt code. My variable 'system_timer' never
gets
> decremented.
>
> unsigned long system_timer, j;
>
> void decrement_timers() __irq
> {
> // occurs 896 times per second
>
> system_timer--;
>
> T0IR |= 1;
> }
>
> int main()
> {
> VPBDIV = 1;
>
> // set up delay timer (TIMER 0)
>
> VICIntSelect = 0; // all interrupts classified as IRQs
> VICVectCntl0 = 0x00000024;
> VICVectAddr0 = (unsigned int) decrement_timers;
> VICIntEnable = 0x00000010;
>
> // Disable Timer0 and Reset Interrupt Flag
>
> T0TCR = 0;
> T0IR |= 1;
>
> T0MR0 = 0;
> T0MCR = 1;
>
> T0CTCR = 0;
> T0PR = 0;
> T0TCR = 1;
>
> // just an infinite loop to check Timer0
>
> system_timer = 4000;
>
> j = 0;
> for(;;)
> {
> j = j + 2;
> }
>
