TMS320F28388D: For up-down count , How to Measure TBCTR Time period

Hi,

I am using TMS320F28388D, and i need to generate 3 phase pwm.

So I configured epwm1 as master and epwm 2,3 as slaves.

I need 40 KHz Switching frequency, so i configured TBPRD as 1250.

TBCLK is 100 MHz and counter mode is up down count.

The counter TBCTR will be changing from 0 to 1250 and 1250 to 0 right.

Now at what rate the TBCTR will be changing. Because when i measure epw1regs.TBCTR through CRO it's time period is 30 msec.  Why it is 30 msec?

Whatever I measured is the right way for checking TBCTR or any other way is there to check the frequency of up down counter. 

Thanks & Regards,

Saikumar.