TMS570LS3137: TMDS570LS31HDK reads a different capture value than Oscilloscope.

Cevdet CIVIR

Part Number: TMS570LS3137

Hi,

I am developing on TMDS570LS31HDK using IAR Embedded Workbench for ARM. I read the pwm with the "capGetSignal" command over the HET1[04] pin in HDK and get the frequency.
While reading a frequency value of 74.2 kHz from the same pin with an oscilloscope, capGetSignal returns 78.5 kHz when I examine it with debug. 
What is the reason for this frequency difference? I am also sharing the Halcogen configurations that I have made below.

Software;

hetSIGNAL_t signalM;
float64 signalFrequency = 0.0F;

while(true)
{

    capGetSignal(hetRAM1, cap2, &signalM);
    
    signalFrequency = 1 / signalM.period;
}