AM437x random shutdown issue

Trent Oshiro

We are using a custom AM437x board with the same PMIC as the AM437x GP EVM. Sometimes our board shuts down after 20 seconds. We have not been able to find a pattern for when it shuts down, it's very random. I have narrowed down the problem to the PMIC PWR_EN signal coming from the RTC_PMIC_EN (AD6) pin on the AM437x. This should always be outputting logic high so the PMIC stays on, but occasionally it does not. If we tie that signal to a 1.8V supply, the board remains on. Is there some way to solve this issue?

Thanks,

Trent

over 9 years ago

0 Manan Patel1 over 9 years ago

Intellectual 390 points

Hi,

This is a question to TI.

The code snippet enabling clocks for RTC is missing from clock_am437x.c but is present in clock_am335x.c. Could this be an issue?

void rtc32k_enable(void)
{
	struct rtc_regs *rtc = (struct rtc_regs *)RTC_BASE;

	/*
	 * Unlock the RTC's registers.  For more details please see the
	 * RTC_SS section of the TRM.  In order to unlock we need to
	 * write these specific values (keys) in this order.
	 */
	writel(0x83e70b13, &rtc->kick0r);
	writel(0x95a4f1e0, &rtc->kick1r);

	/* Enable the RTC 32K OSC by setting bits 3 and 6. */
	writel((1 << 3) | (1 << 6), &rtc->osc);
}

Thanks for your inputs.

Manan.

0 Biser Gatchev-XID over 9 years ago in reply to Manan Patel1

TI__Guru**** 393215 points

Hi Manan,

Do you have an external 32.768kHz crystal? Can you check if it oscillates when this happens?

0 Sunny Guo over 7 years ago in reply to Biser Gatchev-XID

Prodigy 120 points

Hi all, have you solved this problem?

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AM437x random shutdown issue