LP-MSPM0G3507: Timer

Tool/software:

I'm using the sysctl_lfxt_standby_LP_MSPM0G3507_nortos_ticlang project from the mspm0_sdk_2_04_00_06 SDK.

The only change I made in syscfg is setting the Timer Clock Prescaler from 129 to 1.

Based on the code I'm using, one cycle should be 100 ms. However, I'm noticing a 122 µs difference between debug and non-debug modes — it’s 100.143 ms while debugging and 100.265 ms when running normally. So why is there a 122 µs difference?

 #include "ti_msp_dl_config.h"


 #define TIMER_75_MILLISECONDS_TICKS (2458)
 #define TIMER_25_MILLISECONDS_TICKS (820)
 
 int main(void)
 {
     SYSCFG_DL_init();
 
     NVIC_EnableIRQ(TIMER_0_INST_INT_IRQN);
     DL_SYSCTL_enableSleepOnExit();
 
     DL_TimerG_startCounter(TIMER_0_INST);
 
     while (1) {
         __WFI();
     }
 }
 
 void TIMER_0_INST_IRQHandler(void)
 {
     static uint32_t count = TIMER_75_MILLISECONDS_TICKS;
     switch (DL_TimerG_getPendingInterrupt(TIMER_0_INST)) {
         case DL_TIMER_IIDX_ZERO
                 DL_TimerG_stopCounter(TIMER_0_INST);
 
                 if (count > TIMER_25_MILLISECONDS_TICKS) {
                     count = TIMER_25_MILLISECONDS_TICKS;
                 } else {
                     count = TIMER_75_MILLISECONDS_TICKS;
                 }
 
                 DL_Timer_setLoadValue(TIMER_0_INST, count);
             
                 DL_TimerG_startCounter(TIMER_0_INST);
 
             DL_GPIO_togglePins(GPIO_LEDS_PORT,
                 (GPIO_LEDS_USER_LED_1_PIN));
             break;
         default:
             break;
     }
 }