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Booting Issue

Madhura Shetty
Intellectual 810 points

Hi,

Case 1:

DM8148 custom board was not booting from SD card with a valid image. We suspected DDR3 devices and reflowed it. After that we found the issue with two of the DM8148 voltage rails i.e those rails were degraded.(Found while doing cold check- VDDA_USB_1V8,VDDA_PLL_1V8). then we removed DM8148 PMIC to isolate the issue and found the problem to be with DM8148 and replaced it.

Board started working for sometime and suddenly junk characters appeared after 2nd stage boot on UART console. 

We tested DDR3 interface using standalone code provided by TI through JTAG. Tried to read and write DDR registers manually and found BANK1 was not consistent. Hence we replaced BANK 1 DDR Phys and now DDR test is passing. Still the issue is not resolved.I have attached the UART capture file for your reference.dvi_encoder_rev1p0.TXT

Case 2: One of our board under development suddenly stopped booting (PS: It was working initially). We found the same power pins degradation VDDA_USB_1V8,VDDA_PLL_1V8 in this board also.

Please help us to resolve this issue.

Regards

Madhura

  • 0
    TI__Guru**** 170625 points
    Hi Madhura,

    For case 1, how to open the dvi_encoder_rev1p0.TXT UART capture file? Is this standard text file? I can not open with text editor.

    For case 2, power pins degradation can be caused by:
    1. Wrong power sequence
    2. All IO Cells are NOT Fail-safe compliant and should not be externally driven in absence of their IO supply.
    It is not recommended for the DM814x pins to be connected to peripheral signals, which is supplied to a different power supply from powered I/O bank of DM814x power domain.
    If VCC of the periphery is ON and VCC domain of DM814x is OFF, then this state can cause pins degradation to DM814x.

    Regards,
    Pavel