Problem with RTC wide timer in tiva c

Hi Luis,

     What Tiva kit are you using? Post the rest of your code.

     There is some mention about Timer configured in RTC mode at TM4C129 errata.

-kel

Hi ,thanks for your fast answer.

Im using TM4C123GH6PM.

My code:

void ConfigureTimer(void)
{SysCtlPeripheralEnable(SYSCTL_PERIPH_WTIMER1); //enable the timer clock

TimerConfigure(WTIMER1_BASE, TIMER_CFG_RTC);
TimerLoadSet(WTIMER1_BASE,TIMER_A,0);
TimerRTCEnable(WTIMER1_BASE);
TimerEnable(WTIMER1_BASE, TIMER_A);}

int main(void)
{unsigned long ulSysPeriod = SysCtlClockGet();

volatile uint32_t ulSeconds=0;

ConfigureTimer();

SysCtlDelay(ulSysPeriod);
SysCtlDelay(ulSysPeriod);
SysCtlDelay(ulSysPeriod);
SysCtlDelay(ulSysPeriod);
SysCtlDelay(ulSysPeriod);
SysCtlDelay(ulSysPeriod);

ulSeconds= TimerValueGet64(WTIMER1_BASE);

while(1)
{
}
}

First you should use TimerLoadSet64(WTIMER1_BASE,0); since it's a 64bit timer

Look at this, it should help:

http://e2e.ti.com/support/microcontrollers/tiva_arm/f/908/p/251127/890937.aspx#890937

Hi Afonso

I already probe with that and checked that post, the have tye same problem and there is no solution yet.

Thanks

Hello Luis,

In RTC Mode the Clock is supplied on the CCP0 Pin. This clock must be the 32768Hz clock and is then subdivided to get the RTC Counter. Please note that the System Clock "is not" the Clock to the timer but CCP0 pin to the corresponding timer.

So in the code you need to Enable the GPIO for the corresponding Timer, Configure it as the CCP pin and provide an external clock.

Regards

Amit

Hi,thanks for your answer.

Can you tell me what should i put instead of TIMER_CLOCK_SYSTEM, to use a external clock in WT1CCP0 and WT1CCP1?

TimerClockSourceSet(WTIMER1_BASE,TIMER_CLOCK_SYSTEM);

Thanks

Hi Afonso, thanks for your concern 

I want this code to show the date in a LCD, so how can i use the hibernation module?, because i understand that hibernation is used to have a delay in hibernation in seconds.

Thanks 

Hello Luis,

The TIMER_CLOCK_SYSTEM is fine for the timer clock configuration. However the RTC counters are run from a 32KHz clock from the Pad. So what you need is a 32KHx clock source connected to the CCP0 Pad.

Alternatively, you can use the Hibernate Module, which has a RTC Counter and has a dedicated clock that would remove the need for having another 32KHz external clock as suggested by Luis Afonso.

Regards

Amit

Hi 

I've a external 32k clock between WT1CCP0 and WT1CCP1 ,what command should i use to use this external timer? 

Thanks for your time

Hi, thanks to everyone.

Now im using the RTC and it works fine with this code(for future reference):

void ConfigureTimer(void)
{HibernateEnableExpClk(SysCtlClockGet());

HibernateRTCSet(0);
HibernateRTCEnable();}

int main(void)
{

volatile uint32_t ulRTC;//THE SECONDS ARE STORED HERE
volatile uint32_t ulRTCSS;
volatile uint32_t ulRTCSS2;
volatile uint32_t ulRTC1;

ROM_SysCtlClockSet(SYSCTL_SYSDIV_4 | SYSCTL_USE_PLL | SYSCTL_OSC_MAIN |
SYSCTL_XTAL_16MHZ);//SET THE CLOCK TO 50MHz

ROM_SysCtlPeripheralEnable(SYSCTL_PERIPH_SSI0);

SysCtlDelay(SysCtlClockGet()/3);//one second delay

SysCtlDelay(SysCtlClockGet()/3);//one second delay

IntMasterDisable();//disable interruptions for correct readying of registers
do {
ulRTC = HWREG(HIB_RTCC);
ulRTCSS = HWREG(HIB_RTCSS);
ulRTCSS2 = HWREG(HIB_RTCSS);
ulRTC1 = HWREG(HIB_RTCC);
} while ((ulRTC != ulRTC1) || (ulRTCSS != ulRTCSS2));
IntMasterEnable();

while(1)
{
}
}