In this example code, why does the TACCR register is added a value? It's is the coutinuous mode.

the part of code:

// Timer0_A0 interrupt service routine
#if defined(__TI_COMPILER_VERSION__) || defined(__IAR_SYSTEMS_ICC__)
#pragma vector = TIMER0_A0_VECTOR
__interrupt void Timer0_A0_ISR (void)
#elif defined(__GNUC__)
void __attribute__ ((interrupt(TIMER0_A0_VECTOR))) Timer0_A0_ISR (void)
#else
#error Compiler not supported!
#endif
{
P1OUT ^= BIT0;
TA0CCR0 += 50000; // Add Offset to TA0CCR0
}

The sixteen bit CCR register can hold values from 0 to 65535. If the register is currently loaded with let's say 50000 and you add another 50000 to it, you would have 100000, but the register cannot hold this number, so it rolls over. There are 15535 left to 65535, then 1 to roll over to 0 again and then your final value in the register is 34464. In this way you can always add a fixed amount of ticks. The timer running in continuous mode will count from 0 to 65535, roll over to zero and again count up to 65535 and so on. The interrupt fires when the timer hits CCR. So by adding a fixed amount to CCR you add a fixed time that will elapse until the timer again hits the value.

Dennis

1) The interrupt shouldn't fire when TAR is 65535?
2) If it's not, and if the interrupt fires when timer hits CCR, it's like the up mode.
3) By adding always 50000 the CCR will vary to 34464 and a second time to 18911, etc, so this interval would be changed during the program execution?