AM625: AM6254：slow startup speed and can not startup with SD card.

Gary Zeng

Part Number: AM625

Hi Ti expert,

My customer is testing our AM6254 in their own board. Their board is similar with BB's EVM and just change some IO power supply from 1.8V to 3.3V.

Now they met two problems:

1. Compared with BB's EVM, their own board has slow startup speed, up to 10s and then output CCCCCCCC. But if they use BB's EVM, it can immediately output CCCCCCCC.

2. Their own board can output CCCCCCCC with empty emmc but can not output CCCCCCCC when selecting SD card and will get stuck and have not any output.

3. Could you please explain the detailed printed information from BB's board and their own board.

Customer's board:

02000000011a0000616d3632780000000000000048534653010001000100010002a6000000000000d68ecb2c055dff11ade95bd927e837d2a53bc23b0a2800cebce4f106bcf309df2213912d77a157a8b7c2df40672a06a918034aa4c7d603e462481475225d49b8ad0bc40b000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000eaa9efe1ba03e3674e29031bf91542a42b382fdce7cde086d9a75ab19922a005C

BB's board:

01000000011a0000616d36327800000000000000475020200100010001000100CC

We are suspecting that it is related with the IO power supply(1.8V to 3.3V) and POR queue(3.3V delay). Could you please help review the schematic.

7 months ago

0 peaves 7 months ago

TI__Guru 59235 points

I will need a complete schematic to understand how the IO voltage changes may be related to this issue. Was the schematic for this design submitted to TI for review?

Regards,
Paul

0 Gary Zeng 7 months ago in reply to peaves

TI__Prodigy 420 points

FYIA204-ZWJPro-C-4_1_01.pdf

0 peaves 7 months ago in reply to Gary Zeng

TI__Guru 59235 points

I do not see any obvious difference between your SD Card implementation and the BB's SD Card implementation. I also do not see any obvious reason your IO voltage changes would affect SD Card functionality.

I will assign this thread to our software team to see if they can request boot logs and review them to determine what is happening.

Regards,
Paul

0 Gary Zeng 7 months ago in reply to peaves

TI__Prodigy 420 points

Hi Paul,

Thanks for your support.

Look forward to your reply.

0 Prashant Shivhare 7 months ago

TI__Mastermind 48906 points

Hi Gary,

Gary Zeng said:
3. Could you please explain the detailed printed information from BB's board and their own board.

The customer can refer the below FAQ to parse the complete hex string

(7) [FAQ] [AM6XX]: How to check if device type is HS-SE, HS-FS or GP? - Processors forum - Processors - TI E2E support forums

For the other two issues, can you ask the customer to confirm the bootmode they are using? I am guessing it is a combination of the Primary and Backup bootmode where Primary is set to eMMC/SD and Backup to UART. So, when the ROM fails to boot from eMMC/SD, it fallbacks to UART and start dumping the C characters.

Regards,

Prashant

0 Prashant Shivhare 6 months ago in reply to Prashant Shivhare

TI__Mastermind 48906 points

Hello,

Closing the thread due to no update for the last 4 weeks.

In case the issue is still open, please feel free to reply which automatically opens the thread.