ammarshamim,
You can yse ARM built-in SysTick counter to measure amount of CPU cycles taken by a function or operation as shown below. You will be limited by 2^24 CPU ticks only (about 0.25sec @24MHz CPU speed), as SysTick counter on Cortex M0 and M3 can not go beyond SYSTICK_MAXVAL:
#define SYSTICK_MAXVAL 0x00FFFFFF //max allowed SysTick counter value for 24bit
uint32 SysCntVal; // The value of SysTick counter you are trying to retrieve
SysTick_Config(SYSTICK_MAXVAL); //reset counter set to max value, 1-time, will not reload
TCPWM_WritePeriod(); //do something..
SysCntVal = SYSTICK_MAXVAL - (SysTick->VAL); //get elapsed ticks (min offset 3 ticks)
sprintf(strMsg1, "%d, %f\r\n", SysCntVal, x); //report result UART_PutString(strMsg1);
/odissey1
