• State Resolved
  • Locked Locked
  • Replies 3 replies
  • Subscribers 23 subscribers
  • Views 256 views
  • Users 0 members are here
Support feedback
Options
Options
Related

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.

AM6421: AM6421 Boot-up Issue with eMMC

Nikhil Jadhav
Prodigy 100 points

Part Number: AM6421

Hello, we are using AM6421 series processor in one of our designs. We are able to boot the board successfully using SD card but we are facing some issues with eMMC boot. Please refer below seies of events that we tried:

eMMC Part# MTFC32GAZAQHD-IT (Micron)

1) We have booted the board using SD card.

2) Transferred boot image (SBL) to eMMC.

3) We confirmed this transfer by reading back data from eMMC. By doing this, we confirmed that Read/Write is working on eMMC.

4) Next, we have turned OFF the power and set eMMC as primary boot mode.

5) Now, as we are providing the power again. Board is not booting up.

 

eMMC Part# MTFC32GAZAQHD-IT (Micron)

For your reference, I am attaching eMMC schematic pdf.

AM6421_eMMC_Schematic.pdf 

Regards,

Nikhil Jadhav

  • 0
    TI__Genius 13560 points

    Hello Nikhil,

    Can you please provide the current setting of the BOOTMODE switches on the board ? 

    You may also want to read through the eMMC interface related checkpoints in this FAQ: Board bring-up FAQ

    Please allow some time to review the schematic. I will get back to you with a response today EOB or early next week.

     

    Thanks for your patience

    Kind Regards,

    Anastas Yordanov

  • +1 in reply to Anastas Yordanov
    Prodigy 100 points

    Hello Anastas,

    Thanks for quick response.

    There is an update regarding this issue. While checking and verifying eMMC clock and data waveforms, we came to know that assembly house mounted capacitor (pF) instead of all 22 Ohm series resistors at source side of clock. After replacing the same to 22 OHM, we are able to boot the board through eMMC.

    But still, there is one question remains unanswered as below:

    While capacitor is mounted in series of clock, why eMMC is working during normal read/write operation but not working during booting? Is there any specific clock requirement that has to be fulfilled during boot but not during normal read/write?

    Regards,

    Nikhil Jadhav

  • +1 in reply to Nikhil Jadhav
    TI__Mastermind 25090 points

    Hi Nikhil,

    ROM boot is accomplished at much lower speeds to assure boot is successful as much as possible. That could be the reason the capacitor's impedance is enough at higher speeds and not enough at boot speed. One way or another capacitor in place of resistor is not the right option.

    Regards,

    Stan