SK-AM62: AM6254 boot fail from SD card

shang Wang

Part Number: SK-AM62

Hi TI Team,

we refer PROC114E3 demo board, but we delete U75 and U73 for cost down. some board is unstable, they can not boot from SD card sometime. The current is fixed, there are no boot steps. Could you tell me it is whether because of delete those buffer chips?

Thanks.

over 1 year ago

0 Kallikuppa Sreenivasa over 1 year ago

TI__Guru**** 188929 points

Hello Shang Wang,

Thank you for the query.

Would it be possible for you to share the schematics for me to do a quick review and provide my comments.

Regards,

Sreenivasa

0 shang Wang over 1 year ago in reply to Kallikuppa Sreenivasa

Prodigy 10 points

AM6254_sch.pdf

Hi Sreenivasa,

Attached is a part of sch related to SD card boot for your review.

Thanks,

0 Kallikuppa Sreenivasa over 1 year ago in reply to shang Wang

TI__Guru**** 188929 points

Hello Shang Wang,

Thank you.

we refer PROC114E3 demo board

Are you using crystal or oscillator? I assume you are using discrete power solution similar to proc114.

Regards,

Sreenivasa

0 shang Wang over 1 year ago in reply to Kallikuppa Sreenivasa

Prodigy 10 points

Hi Sreenivasa,

we are using oscillator as TI demo board, and just use PMIC TPS621903 to power AM6254, other part use discrete power solution. But we delete U22 and some other gate which related with reset, just remain the gpio reset and power up reset.

Thank you.

+1 Kallikuppa Sreenivasa over 1 year ago in reply to shang Wang

TI__Guru**** 188929 points

Hello Shang Wang,

Thank you.

Could you please reduce the series resistor value to 0R.

Also can you please probe the MCU_PORz and the oscillator

The oscillator is expected to be stable before MCU_PORz is released.

Can you also confirm the SD card pullups are mounted.

Please check if there is a pulldown on the MMC1_CLK near to the SoC. if there is a pulldown, please DNI the pullup.

Regards,

Sreenivasa

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SK-AM62: AM6254 boot fail from SD card