tm4c129 HibernateEnableExpClk

Hi,

    Provide, more details. See, link at my sticky "Information to provide when asking for help". Also, post your code here.

- kel

Hello Yuan,

That is correct. If the crystal is not mounted the use of external clock will cause the function to hang.

If the accuracy is not the problem, then you can use the internal hibernate oscillator as the clock source.

HibernateClockConfig(HIBERNATE_OSC_LFIOSC);

Regards

Amit

void init_RTC(void)
{
uint32_t g_ui32SysClock, ui32Len;
//
// Enable the hibernate module.
//
g_ui32SysClock = MAP_SysCtlClockFreqSet((SYSCTL_XTAL_25MHZ | SYSCTL_OSC_MAIN | SYSCTL_USE_PLL | SYSCTL_CFG_VCO_480), 120000000);

SysCtlPeripheralEnable(SYSCTL_PERIPH_HIBERNATE);

HibernateEnableExpClk(g_ui32SysClock);

//
// If the wake was not due to the above sources, then it was a system
// reset.
//

HibernateClockConfig(HIBERNATE_OSC_LOWDRIVE);

//
// Enable RTC mode.
//
HibernateRTCEnable();

//
// Configure the hibernate module counter to 24-hour calendar mode.
//
HibernateCounterMode(HIBERNATE_COUNTER_24HR);
IntMasterEnable();
init_setTime();
}

after "HWREG(HIB_CTL) |= HIB_CTL_CLK32EN;" th WRC bit is always 0

Hello Yuan,

It should be as follow if external crystal is not provided

g_ui32SysClock = MAP_SysCtlClockFreqSet((SYSCTL_XTAL_25MHZ | SYSCTL_OSC_MAIN | SYSCTL_USE_PLL | SYSCTL_CFG_VCO_480), 120000000);

SysCtlPeripheralEnable(SYSCTL_PERIPH_HIBERNATE);

HibernateClockConfig(HIBERNATE_OSC_LOWDRIVE);

HibernateEnableExpClk(g_ui32SysClock); // This is not required

...

Regards

Amit

hello Amit,

thanks,the accuracy is a problem,so i need the 32.768khz crystal,i want to know the /hib pin is a problem if it's floating

Hello Yuan,

If accuracy is the problem then you would need a 32768Hz crystal. Also please do make sure that you o through the TM4C129 System Design Guidelines for Crystal Selection and capacitor selection.

As for the /HIB pin, if it is not to be used in your design then you can keep it floating.

Regards

Amit

Hello Amit,

thanks for your  patient,i don't how to do that,the  capacitor we select 22pf,the data sheet is 12~ 24pf,so it't not a problem,the pins are fixed,neen't to set,so ....

Hello Yuan

Please go through the section 3.6.1.2 of the TM4C129 System Design Guidelines

http://www.ti.com/lit/an/spma056/spma056.pdf

The equations in this section along with the crystal selected (CL from the cyrstal spec) can be used to find if C1 and C2 values are correct or not.

Regards

Amit

Hello Amit,

if the cs=3pf,the cl=14pf, is correct or not?

Hello Yuan

Yes, the 22pF is correct by the equation for the above mentioned parameters.

Regards

Amit

Hello Amit,

now,i put the crystal replaced by oscillator,and can work normally,so I is it right ? can be considered oscillator problem?

now,i put the crystal replaced by oscillator,and can work normally,so I is it right ? can be considered crystal oscillator problem?

Hello Yuan

Yes, you can put the crystal now. Do make sure that

(a) The code is also updated to use the crystal and not the internal oscillator

(b) The capacitors are mounted as per the System Design Guidelines and routing guidelines adhered to before powering up the device.

Regards

Amit