• State Resolved
  • +1 person also asked this people also asked this
  • Locked Locked
  • Replies 5 replies
  • Subscribers 104 subscribers
  • Views 139 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

AM62A7: Emmc power down interface

Shawn
Prodigy 100 points
Part Number: AM62A7

Tool/software:

HI experts，

Background: During shutdown, the SOC needs to save the data and needs to power down the EMMC, is there a relevant interface to do this?

The current idea is that the SOC provides the underlying interface, and the upper layer service calls the interface to power down the EMMC; re-powering requires a reboot of the EMMC. Is this feasible?

Best Regards

  • 0
    TI__Expert 5070 points

    Hi Shawn,

    if you want to save some data, why you are asking for shutting down emmc, I think when you power off the board, the emmc will power off accordingly, you don't need to control it using SW, if you just want power down emmc.

    BR,

    Biao

  • 0 in reply to Biao Li
    Prodigy 100 points

    HI Biao

    If the board suddenly powers down during a write/read of data to the emmc, is there any data protection or anything on this part?

    Best Regards

  • 0 in reply to Shawn
    TI__Guru*** 149151 points

    Hi Shawn,

    Are you asking for the scenario of sudden power loss or software triggered power down?

  • 0 in reply to Bin Liu
    Prodigy 100 points

    Hi Bin,

    For example, now power has a state that can be used to prepare for power down to avoid system anomalies, when entering this power state, the SOC, DM core needs to be ready for power down such as file data storage, when this power state 10s timeout when the power is cut off.

    Best Regards

  • 0 in reply to Shawn
    TI__Guru*** 149151 points

    Hi Shawn,

    Sorry, it is still unclear to me about the scenario you described. But regardless, the eMMC device itself doesn't need power-down. You might just need to flash the cached data to eMMC before system power down to keep data integrity.

    In general, there are two cases that either sudden power loss or software triggered/aware power down.

    In the first case, there won't be any time for software to flash cached data to eMMC. If you use Linux, journal filesytem might help in this case. If system power loss happens during eMMC write is in progress, the data would be corrupted. You would need backup battery to provide time for software to finish the eMMC write.

    In the second case, software has enough time to finish eMMC write then trigger system power down. In Linux, using poweroff command is one of the examples.