TM4C129 Log time duration and clock frequecy

Paulo Freitas de Araujo Filho

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

over 8 years ago

0 Dennis Eichmann over 8 years ago

Guru 74080 points

Hi Paulo!

Maybe better place your request in the TM4C microcontroller forum:

Dennis

0 Chester Gillon over 8 years ago

Guru 92251 points

Paulo Freitas de Araujo Filho said:
The thing is, this time duration is bigger for a 120MHz clock than for a 16MHz clock, which doesn't make sense.

Can you confirm if you are comparing raw clock cycle measurements for the duration, or clock cycles converted to time according to the device frequency?

When running from flash with a 120MHz clock the number of clock cycles might be more than with a 16MHz due to the flash wait states which are required at higher clock frequencies. However, due to the faster clock frequency the absolute time duration should be less.

0 DavidL over 8 years ago

TI__Mastermind 25045 points

Your post has been moved to the TM4C Microcontrollers Forum as I believe they should be able to provide you with the information that you need.

0 cb1 over 8 years ago in reply to DavidL

Guru 47900 points

Perhaps a THIRD such move will, "Do the trick!"

0 Chester Gillon over 8 years ago in reply to cb1

Guru 92251 points

I think this question has been answered in another thread, see Tivaware SysCtlClockFreqSet cpu clock

0 Paulo Freitas de Araujo Filho over 8 years ago in reply to Chester Gillon

Prodigy 110 points

Yes, sorry guys.

Arm-based microcontrollers

Arm-based microcontrollers forum

TM4C129 Log time duration and clock frequecy