TM4C129 Log time duration and clock frequecy

Hi,

I am using Log_write1 to get the duration between two points of my code (AES encryption) using a TM4C129. The thing is, this time duration is bigger for a 120MHz clock than for a 16MHz clock, which doesn't make sense.

Any one can clarify me on this? Any possibilities to explain it?

Thanks,

Paulo