• TI Thinks Resolved

AM3352: RTC modes support

Genius 11290 points

Replies: 3

Views: 140

Part Number: AM3352

Hi,

a customer needs the RTC modes with ALARM event wakeup for the AM3352 (e.g. Beaglebone with TPS65217).

I looked at the TI PSDK Linux documentation at

http://software-dl.ti.com/processor-sdk-linux/esd/docs/latest/linux/Foundational_Components_Kernel_Drivers.html#id42

RTC-Only and RTC+DDR Mode

The LCPD release also supports two RTC modes depending on what the specific hardware in use supports. RTC+DDR Mode is similar to the Suspend/Resume above but only supports wake by the Power Button present on the board or from an RTC ALARM2 Event. RTC-Only mode supports the same wake sources, however DDR context is not maintained so a wake event causes a cold boot.

RTC-Only mode is supported on:

  • AM437x GP EVM
  • AM437x SK EVM

RTC+DDR mode is supported on:

  • AM437x GP EVM

Whether or not your board enters RTC-Only mode or RTC+DDR mode depends on the regulator configuration and whether or not the regulator that supplies the DDR is configured to remain on during suspend. This is supported by the TPS65218 in use of the AM437x boards but not the TPS65217 or TPS65910 present on AM335x boards.

All of this is supported with the AM437x. Can we get this supported with the AM335x as well?

Apparently there have been some older kernels L3.x where RTC modes were supported.

Thanks!

--Gunter

  • Hello Gunter,

    I am checking on the AM335x vs AM437x question. However, it sounds like the issue is that TPS65217 does not support RTC low power modes, while TPS65218D0 does. See AM335x PMIC Selection Guide. Is the customer willing to use TPS65218D0?

    Regards,

    Nick

  • Hi,

    The sleep and wake cycle is being implemented on the BeagleBone Green Wireless and we are locked into that hardware.  We do have flexibility into "how deep" the sleep is--it could be anywhere from DRAM-still-active to Shutdown, and wakeup or bootup time is not constrained.

    Steve.

  • In reply to Steve Narciso:

    Hello Steve & Gunter,

    I apologize for the delayed response. RTC-Only and RTC+DDR Mode are only supported with TPS65218D0 - we cannot use them with TPS65217 . Please take a look at the other low power options in our Power Management documentation - search for subsection "Suspend/Resume Support".

    Regards,

    Nick