Part Number: TM4C1294NCPDT
I have two launchpad boards EK- TM4c1294 , In my application i need to synchronize time between two boards , for that one board act as master and other as slave
Master sends a signal using gpio interrupt to slave board (At same time Master RTC is enabled), upon receiving interrupt signal through gpio slave starts
its own RTC ,
Both master and slave are set for match interrupt in hibernate rtc module at time 65 seconds and 12458 subseconds . Inside interrupt handler i am toggling
gpio and examining both signal in oscilloscope tektronix 2012 . The toggling pulses in oscilloscope are apart from some 250 us .
On repeating i am getting same result .
Now my question is , can rtc in different chips can have different accuracy or it has to do something with on chip crystal accuracy .
Both boards are from TI , i am using external crystal for accuracy it has 12 pf capacitor attached to it as per schematic .
This is my rtc init subroutine :
{
SysCtlPeripheralEnable(SYSCTL_PERIPH_HIBERNATE);
while(!SysCtlPeripheralReady(SYSCTL_PERIPH_HIBERNATE));
HibernateEnableExpClk(g_ui32SysClock);
HibernateClockConfig(HIBERNATE_OSC_LOWDRIVE);
HibernateRTCEnable();
HibernateRTCSet(0);
HibernateRTCMatchSet(0,65);
HibernateRTCSSMatchSet(0,12458);
HibernateIntEnable(HIBERNATE_INT_RTC_MATCH_0);
HibernateIntClear(HIBERNATE_INT_PIN_WAKE | HIBERNATE_INT_LOW_BAT | HIBERNATE_INT_RTC_MATCH_0);
HibernateIntRegister(HibernateHandler);
}
If i change slave or master with other boards then difference vary with board but remain same for a pair .
Thanks & Regards .
