TMS320F280039C: The issue about system frequency

Part Number: TMS320F280039C

Hi Teams

We met another issue during testing XF280039C, that seems about the accuracy of the system frequency, and it cause the abnormal inverter control.

Here is the waveform about xlkout and switch frequency, from the waveforms, we can see the actual value is more than the expected by 0.45%.

We also check the external crystal, the frequency is 10MHz, that is normal.

Below is the configure code for system frequency and xlkout. Due to TIOS don’t support F280039C, and the main affect part is clock configuration. So we configurate cpu frequecy again when enterinto main(), that make TIOS can also work in F280039C, as below code.

Int main(void)
{
    xdc_runtime_Types_FreqHz cpufreq;

    InitSysCtrl();
    // Don't operate IER IFR Flag, Don't init PIE in SYSBIOS
    // Refreash the clock tick setting
    cpufreq.hi = 0;
    cpufreq.lo = 120000000L;
    BIOS_setCpuFreq(&cpufreq);
    Clock_tickReconfig();
    ...
    ...
    ...
    BIOS_start();    /* does not return */
    return(0);
}

Configurated the system frequency to 120MHz by using external crystal, And set xclkout to 30MHz.

Based on above info, please help to check the cause of the issue about accuracy of frequency, thanks in advance!