CSM slow down the execution of the application, reduces the speed, Does it affect the clock frecuency? With TMS320F28335.

Hi:

After hours tryng to find some explanation or commentary throughout the documentation, wiki and forum, I resort to this forum to ask for it.

We have a time critical application running on the  TMS320F28335, which we develop and debug with the CCS.

We measure the execution time of one of the most time-critical functions, both with timer1 and with chronometer measurement of a led toggling every 1000 executions of the function, and find that, without CSM password lock, it executes in about 0.7 ms. However, if we "Program Password" (from the CCS On-Chip flash button and "Lock", and we launch the stand-alone execution, we measure (with the led toggling) that the execution time rises to about 3 ms. 

I suppose it won't have any influence on this, but, on top of the same "On-Chip Flash (TMS320C28XX) titled form, the Clock Configuration square has its default values of OSCCLK (MHz) , CLKINDIV and PLLCR Value fields filled to 30, 2 and 10, respectively. (In fact, the clock configuration I beleive is done in the following main called function:

void InitSysCtrl(void)
{

// Disable the watchdog
DisableDog();

// Initialize the PLL control: PLLCR and DIVSEL
// DSP28_PLLCR and DSP28_DIVSEL are defined in DSP2833x_Examples.h
InitPll(DSP28_PLLCR,DSP28_DIVSEL);

// Initialize the peripheral clocks
InitPeripheralClocks();

}

, where DSP28_PLLCR and DSP28_DIVSEL are defined in DSP2833x_Examples.h as:

#define DSP28_DIVSEL 2 // Enable /2 for SYSCLKOUT

#define CPU_RATE 6.667L // for a 150MHz CPU clock speed (SYSCLKOUT)

Could anybody, please, give us any explanation about it? 

Thanks and regards,

Jose