AM3352: DDR init failure

Part Number: AM3352
Other Parts Discussed in Thread: TPS65218D0, , TPS65217

Hi TI Champs

There's a request from Customer who met a boot failure on thier 1st custom board with AM3352 and TPS65218D0.

Their CPU board which referenced MYiR with TPS65217 works fine along with their separeated carrier board.

However they attached TPS65218D0 which was recommended by TI earlier. and it still doen't work on their 1st costom board.

When they tried to attach JTAG trace, It unable to pass dram_init().

They could not figure out any problamatic point from their schematic.

Could you please check the interface btw AM3352 and DDR including PMIC TPS65218D0?

DTNS-MOD_REVA_DSN.pdf

Also attached their cpatured power signal level.

DCDC1(VDD_CORE/1.1V): 1.11V
DCDC2(VDD_MPU/1.1V): 1.11V
DCDC3(VDD_VDDQ_DDR/1.35V): 1.36V
DCDC4(VDD_3P3/3.3V): 3.32V
DCDC5(VDD_RTC/1V): 0.969V
DCDC6(VDDS_RTC/1.8V): 1.79V
LDO1(VDD_1P8/1.8V): 1.78V
LS1(VDDS_DDR/1.35V): 1.33V

DTNS MPU_ PMIC TPS65218D0 voltage_level_220720.zip

Please check the schematic and voltage level captured from PMIC.

Thanks.

Regards,

Jack

over 3 years ago

0 Kalyan Gajjala over 3 years ago

TI__Prodigy 640 points

Hi Jack,

Thank you for reaching out,

To check the power sequencing order.

Please share the capture with sequencing order of VDD_CORE, VDD_MPU, PWRONRSTn and CLK_M_OSC in one image.

Also another capture with sequencing order of 1.8V, VDDS_DDR and 3.3V.

Regards,

Kalyan.

0 JK over 3 years ago in reply to Kalyan Gajjala

Mastermind 8599 points

Hi Kalyan

Please find the Sequnce Waveform of Power Signals below.

Thanks.

Regards,

Jack

0 Kalyan Gajjala over 3 years ago in reply to JK

TI__Prodigy 640 points

Hi Jack,

Thank you for the waveforms. Let me review.

Regards,

Kalyan.

0 JK over 3 years ago in reply to Kalyan Gajjala

Mastermind 8599 points

Hi Kalyan

Can you give me an estimated schedule when I can get feedback?

Thanks & Regards,

Jack

+1 Kalyan Gajjala over 3 years ago in reply to JK

TI__Prodigy 640 points

Hi Jack,

Apologies for the delayed reply.

Power Sequence looks fine.

Please try with the below changes

DDR_RSTn_PROC is connected to PMIC GPIO1 which has minimum high-level input voltage as 1.3V. If DDR_RSTn_PROC is below 1.3V then GPIO1 may not detect logic high and eventually logic high can not pass through GPO2 to release the reset.
Shunt DDR_RSTn_PROC with DDR_RSTn by removing R39, R42 and insert R78 resistors.
Terminate DDR3L reset pin with 1.5Kohm pulled up to VDDS_DDR supply closer to DDR3L memory.

Regards,

Kalyan.

+1 Kallikuppa Sreenivasa over 3 years ago in reply to Kalyan Gajjala

TI__Guru**** 172624 points

Hi Jack,

In continuation to the above note by Kalyan, I am adding additional comments

The Beagle bone black available for purchase below also seems to be based on TPS65217 and the board is pretty poplar

https://beagleboard.org/black

However they attached TPS65218D0 which was recommended by TI earlier. and it still doen't work on their 1st costom board.

Do you have some thoughts on the source of the reference schematics that you have used.

The DDR reset implementation seems to have some difference.

(+) TPS65218D0: TPS65218D0+AM335x reference design - Power management forum - Power management - TI E2E support forums

https://e2e.ti.com/support/power-management/f/196/t/959994?TPS65218D0-AM335x-TPS65218D0-hardware-reference-design

There are multiple versions for you to review.

Kalyan has analyzed the changes and provided the recommendations on the changes to be made for testing

Please test the board with the suggested changes and let us know your findings.

Regards,

Sreenivasa

0 JK over 3 years ago in reply to Kallikuppa Sreenivasa

Mastermind 8599 points

Hi Kallikuppa Sreenivasa

They already have BBB board based on TPS65217, And their custom carrier board does work with 65217 based CPU board. But the their new CPU Board based on TPS65281D0 still does not work. Unable to pass DDR init.

The TPS65218D0 has been recommended by TI earlier. I remember there's issue with 65217 bug. Hence I've recommended customers to use 65218D0 recently.

I'll get back to you after testing with rocomendations above.

Thanks.

Regards,

Jack

0 Kallikuppa Sreenivasa over 3 years ago in reply to JK

TI__Guru**** 172624 points

Hello Jack,

Thank you for the note.

Our review and observations are based on the inputs you provided and thank you for the efforts.

Looking forward to the results.

If you have the 65217 based CPU board information that could be shared, i can do a quick check.

Regards,

Sreenivasa

0 JK over 3 years ago in reply to Kallikuppa Sreenivasa

Mastermind 8599 points

Hi Sreenivasa

I saw they used MYIR SOM based design reference. also tried to make the same PCB with TPS65218D0.

There's no their own PCB design with TPS65217 yet.

TPS65218D0 based PCB is their first design.

http://www.myirtech.com/list.asp?id=494

Thanks.

Regards,

Jack

0 Kallikuppa Sreenivasa over 3 years ago in reply to JK

TI__Guru**** 172624 points

Hello Jack,

Thank you for the inputs.

Looking forward for the test results.

If customer has access to the MyIR module schematic, it would be a good idea to compare the PMIC interface and DDR reset termination.

Regards,

Sreenivasa

0 Kallikuppa Sreenivasa over 3 years ago in reply to Kallikuppa Sreenivasa

TI__Guru**** 172624 points

Hello Jack,

Checking if customer was able to perform some testing ?

Regards,

Sreenivasa

0 JK over 3 years ago in reply to Kallikuppa Sreenivasa

Mastermind 8599 points

Hi Sreenivasa

They could not proceed the testing becaue there're no TP or 0ohm resistor on the singal.

They ordered a new PCB revision for your recommended testing.

I'll get back to you after closing this thread since the current HW revision does not have appropriate test methods.

Thanks.

Regards,
Jack

0 Kallikuppa Sreenivasa over 3 years ago in reply to JK

TI__Guru**** 172624 points

Hello Jack,

Thank you for the message and noted

Regards,

Sreenivasa

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AM3352: DDR init failure