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Original question:
Hi,
I am using timer0 to generate an interrupt every 1 second. This is working fine, but now I want to use the prescaler in order to increase the interrupt period to any number of seconds. If, with no prescaler, I am getting an interrupt every 1 second, I expect that setting the prescaler to 1 I will get an interrupt every 2 seconds and so on, but this is not working.
The code where I initialize timer0:
void timer0_init(void){
// We assume that the system clock frequency is 40MHz -> T = 25ns
/* Enable 16/32-Bit Wide General-Purpose Timer0 clock in Clock Gating Control */
SYSCTL_RCGCTIMER_R |= 0x01;
/* Ensure timerA is disabled before modifying it */
TIMER0_CTL_R &= ~0x01;
/* Select 32-Bit configuration */
TIMER0_CFG_R = 0x00000000;
/* Configure timer as periodic, count down and other functionalities as needed */
TIMER0_TAMR_R = 0x02;
/* Load start value */
TIMER0_TAILR_R = 0x26259ff; //40MHz -> to generate an interrupt every second, value to load: 40.000.000 - 1 = 39.999.999 -> 0x26259ff
// PRESCALER ??? does not have any effect
TIMER0_TAPR_R = 0xff; // tried with different values with no effect
/* Enable Timer0 interrupt in NVIC */
ROM_IntEnable(INT_TIMER0A);
/* Enable interrupt */
TIMER0_IMR_R |= 0x01;
/* Start counting */
TIMER0_CTL_R |= 0x01;
}What am I missing?
Thanks
