USB configuration conflicts with RTC_SetTime

abelloni · ‎2013-10-31

Posted on October 31, 2013 at 15:08

Hi everybody,

I'm using a STM32 L152CB microcontroller with external clock. Initially I used it without USB and the RTC_SetTime worked. Since I configured the USB, the function (RTC_SetTime) doesn't work and my RTC_TimeTypeDef struct is always to 0 for each parameters (day, month, etc..)

The micro's frequency is 16Mhz and the USB's clock is 48Mhz.

Have you suggestions?

Thanks!

#rtc #clock #usb

chen · ‎2013-11-01

Posted on November 01, 2013 at 12:16

Check your interrupt set up.

You mentioned the RTC is an external device - does it use IRQs??

The USB code relies heavily on IRQs, this may be interfering with the RTC code.

Amel NASRI · ‎2013-11-01

Posted on November 01, 2013 at 13:37

Is the function ''RTC_SetTime'' reached or the execution is stuck somewhere before?

Try to check this.

-Mayla-

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Tesla DeLorean · ‎2013-11-01

Posted on November 01, 2013 at 14:45

I'm not entirely convinced there is a conflict between the RTC and USB.

Perhaps you can modify a VCP or MSC example to demonstrate this?

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kevin1078 · ‎2014-10-13

Posted on October 13, 2014 at 09:44

I also encountered this problem. It's stuck at RTC_EnterInitMode, waiting for RTC_ISR_INITF flag to be set. It succeeds before USB_Start, whereas fails after it.

waclawek.jan · ‎2014-10-13

Posted on October 13, 2014 at 10:13

When stuck, read out and post the content of RTC_ISR and RCC_CSR registers.

JW

kevin1078 · ‎2014-10-13

Posted on October 13, 2014 at 10:32

In STM32L1XX_StdPeriph_Lib_V1.2.0, there is no RCC_CSR, do you mean RCC_CR?

RCC_ISR: 0x00000234 (I also saw 0x0000003F before), RCC_CR: 0x00007340.

This stuck occurs right after the following code:

/*** Set interrupt mask ***/

wInterrupt_Mask = CNTR_RESETM | CNTR_SUSPM | CNTR_WKUPM;

_SetCNTR(wInterrupt_Mask);

Regards,

waclawek.jan · ‎2014-10-13

Posted on October 13, 2014 at 10:54

> In STM32L1XX_StdPeriph_Lib_V1.2.0, there is no RCC_CSR, do you mean RCC_CR?

Who cares about the ''library''? See RM0038 ch.5.3.14.

>This stuck occurs right after the following code:

>

>/*** Set interrupt mask ***/

> wInterrupt_Mask = CNTR_RESETM | CNTR_SUSPM | CNTR_WKUPM;

> _SetCNTR(wInterrupt_Mask);

I have no idea, what is _SetCNTR(). Before, you told us that the stuck occurs at waiting for RTC_ISR.INITF. Show us the real code.

JW

kevin1078 · ‎2014-10-13

Posted on October 13, 2014 at 11:10

Sorry, I typed RCC->CSR as RTC->CSR and got no result.

RTC->ISR: 0x00000234

RCC->CSR: 0x1E410300.

Code:

ErrorStatus RTC_EnterInitMode(void)

{

__IO uint32_t initcounter = 0x00;

ErrorStatus status = ERROR;

uint32_t initstatus = 0x00;

/* Check if the Initialization mode is set */

if ((RTC->ISR & RTC_ISR_INITF) == (uint32_t)RESET)

{

/* Set the Initialization mode */

RTC->ISR = (uint32_t)RTC_INIT_MASK;

/* Wait till RTC is in INIT state and if Time out is reached exit */

do

{

initstatus = RTC->ISR & RTC_ISR_INITF;

initcounter++;

} while((initcounter != INITMODE_TIMEOUT) && (initstatus == 0x00));

if ((RTC->ISR & RTC_ISR_INITF) != RESET)

{

status = SUCCESS;

}

else

{

status = ERROR;

}

else

{

status = SUCCESS;

}

return (status);

}

INITMODE_TIMEOUT = 0x2000

Thanks.

kevin1078 · ‎2014-10-13

Posted on October 13, 2014 at 11:51

About _SetCNTR:

#define RegBase (0x40005C00L) /* USB_IP Peripheral Registers base address */

/* Control register */

#define CNTR ((__IO unsigned *)(RegBase + 0x40))

#define _SetCNTR(wRegValue) (*CNTR = (uint16_t)wRegValue)

this function operates USB_CNTR register.