Linux/AM3354: Board bringup issue

hontel lea

Part Number: AM3354

Tool/software: Linux

reference to tmdxice3359,I design a circuit board,but not work.The power chip is TPS65910A3A1,power worked right, every output is normal.Compared to the development board, power chips and ARM are more hot。

The sysboot is set 10111，Boot Sequence is MMC0,SPI0, UART0, USB0. and TF card was empty.After power-up, uart0 does not have any printouts。

This question has been a long time, and urge you to help look at the schematic, to confirm what the design error, very grateful! thank。

over 8 years ago

0 Biser Gatchev-XID over 8 years ago

TI__Guru**** 393215 points

You may have schematic and/or layout errors. You may refer to this wiki for guidelines to board bringup: processors.wiki.ti.com/.../AM335x_board_bringup_tips

If you require a schematic review you must contact your nearest TI representative, this cannot be done through the forum.

0 hontel lea over 8 years ago in reply to Biser Gatchev-XID

Prodigy 130 points

hi,thanks very much.maybe there are errors in my schematic.but i checked again and again,cannot find it,reference to guide,i cannot get more helpful results.

0 hontel lea over 8 years ago in reply to Biser Gatchev-XID

Prodigy 130 points

Hello,Now,i find that the voltage of CAP_VDD_SRAM_CORE is wrong, the value is 80mV. but the TPS65910A3A1 is work right, each channal voltage is ok. pls help me.

0 Biser Gatchev-XID over 8 years ago in reply to hontel lea

TI__Guru**** 393215 points

CAP_VDD_SRAM_CORE should be decoupled with 1uF capacitor to GND, with no other external connections. Is this a single board or you see the same issue on multiple boards?

0 hontel lea over 8 years ago in reply to Biser Gatchev-XID

Prodigy 130 points

Now,CAP_VDD_SRAM_CORE = 1.2V;CAP_VDD_SRAM_MPU = 1.2V;CAP_VBB_MPU = 1.1V;CAP_VDD_RTC = 1.1V are right.But don't print CCCCC.the uart0 's Tx no signal.

0 Biser Gatchev-XID over 8 years ago in reply to hontel lea

TI__Guru**** 393215 points

Is this a single board or you see the same issue on multiple boards?

0 hontel lea over 8 years ago in reply to Biser Gatchev-XID

Prodigy 130 points

yes,all do not print.

0 hontel lea over 8 years ago in reply to Biser Gatchev-XID

Prodigy 130 points

together 4 boards.Anyone cannot start and print.

0 Biser Gatchev-XID over 8 years ago in reply to hontel lea

TI__Guru**** 393215 points

OK, do you have anything connected on SPI0?

0 hontel lea over 8 years ago in reply to Biser Gatchev-XID

Prodigy 130 points

A chip of flash,but now it has been moveout.the board is empty.

0 Biser Gatchev-XID over 8 years ago in reply to hontel lea

TI__Guru**** 393215 points

Can you post the schematic? I will take a look.

0 hontel lea over 8 years ago in reply to Biser Gatchev-XID

Prodigy 130 points

(removed)

thanks a lot.

0 hontel lea over 8 years ago in reply to Biser Gatchev-XID

Prodigy 130 points

reference to tmdxice3359 schematic,the reset circuit has been edited. the chips of u20 an u21 have been moveouted, and the 3 pin of u21 was conected directly to the 5 pin of u21. and the resistor R119 has been replaced by a 0.01uF capacitor.

0 Biser Gatchev-XID over 8 years ago in reply to hontel lea

TI__Guru**** 393215 points

At first look you do not have external pullups to VDDSHV6 on processor EMU0 and EMU1 signals. These are required for proper startup. Read Errata Advisory 1.0.36.

Another thing is that you should connect both oscillator grounds to the common GND. Read Errata Advisory 1.0.30.

0 hontel lea over 8 years ago in reply to Biser Gatchev-XID

Prodigy 130 points

Thank you very much, the schematic is not there are other mistakes, perhaps I need a new circuit board to test, hope that the error on the schematic can be corrected

0 hontel lea over 8 years ago in reply to Biser Gatchev-XID

Prodigy 130 points

Now,I pull up the EMU0,and leave the EMU1 to be suspended, The board can work and print "CCCCCCCC".

Thank a lot!

0 hontel lea over 8 years ago in reply to hontel lea

Prodigy 130 points

Hello, thank you very much for your help. Does the second point mean that I should remove the resistors R21 and R23,and connect the VSS_OSC and VSS_RTC to ground (DGND) directly.

0 Biser Gatchev-XID over 8 years ago in reply to hontel lea

TI__Guru**** 393215 points

Yes, connect VSS_OSC and VSS_RTC to ground (DGND) directly.

0 hontel lea over 8 years ago in reply to Biser Gatchev-XID

Prodigy 130 points

Thank you very much for your help,The problem can be solved quickly.
Thanks again.

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Linux/AM3354: Board bringup issue