TMS320C6670 Frequency

Anugerah Firdauzi

Hello,

I am using TMS320C6670 EVM and CCS 5. I need to determine the execution time of program, so I use function clock() before and after the program lines which I want to measure the execution time and calculate the result. The simple diagram is as follow

#include <time.h>

int t1,t2,t;

t1=clock();

////Line of programs

t2=clock();

t=t2-t1;

Well, by enabling the clock profiling in Run --> Clock after launch the EVM and before connecting the core (because I get different setup if I enable clock after connecting the core) , I can get the number of cycles of the program. So my questions are

1. What is the frequency of the 6670 EVM? How to determine it? Is it different between each core?

2. Will the EVM frequency be different if I load the gel file before I run the program?

3. Does the clock cycle result supposed to be the same if I use gel file compared to don't use it?

Can somebody help me please? I'll appreciate for some help.

Thank you

over 13 years ago

0 Chad Courtney over 13 years ago

TI__Mastermind 30825 points

1.) The EVM should be setup by default to operate at 1GHz, all cores use a common core clock (SYSCLK), so all cores will always run at the same clock rate. You can look at the PLL settings (see the Data Manual which can be found on the TMS320C6670 product page) or probe the SYSCLKOUT pin. The SYSCLKOUT operates at 1/6 of the SYSCLK

2.) If the GEL file changes the PLL configures, then yes it can change the PLL setting.

3.) The EVM should first boot via I2C and it should configure the PLL for 1GHz setting. The GEL file should be default be setup to configure the EVM for 1GHz operation as well. You can open the GEL file and look for items relate to PLL1, you should see a PLL1_M and PLL1_D values set and a table, and if you execute the script to init the PLL1 with these values it will configure for 1GHz operation.

That said, if you're using internal memory and testing functions, then the cycle count would be the same whether or not you're operating at 800MHz or 1.2GHz.

Best Regards,
Chad