About the TMS320f28335 timer

Hi Ameer,

Ameer Janabi said:

My question is what is the limit for minimum period, and what is the method to do a very low period so i can have high precision with the counter!

The above routine can achieve as low as 1us.

Here's the routine you can further analyze:

void ConfigCpuTimer(struct CPUTIMER_VARS *Timer, float Freq, float Period)
{
    Uint32     PeriodInClocks;

    // Initialize timer period:
    Timer->CPUFreqInMHz = Freq;
    Timer->PeriodInUSec = Period;
    PeriodInClocks = (long) (Freq * Period);
    Timer->RegsAddr->PRD.all = PeriodInClocks - 1;

    // Set pre-scale counter to divide by 1 (SYSCLKOUT):
    Timer->RegsAddr->TPR.all  = 0;
    Timer->RegsAddr->TPRH.all  = 0;

    // Initialize timer control register:
    Timer->RegsAddr->TCR.bit.TSS = 1;      // 1 = Stop timer, 0 = Start/Restart Timer
    Timer->RegsAddr->TCR.bit.TRB = 1;      // 1 = reload timer
    Timer->RegsAddr->TCR.bit.SOFT = 0;
    Timer->RegsAddr->TCR.bit.FREE = 0;     // Timer Free Run Disabled
    Timer->RegsAddr->TCR.bit.TIE = 1;      // 0 = Disable/ 1 = Enable Timer Interrupt

    // Reset interrupt counter:
    Timer->InterruptCount = 0;
}

Regards,

Gautam