[HELP]. Hardware bring-up failed with external Crystal 27MHZ

Hi Cao,

In DM816x TI EVM, ABM7-27.000MHZ-D2Y-T crystal is used. It looks like your crystal parameters are the same and should work fine. But you can check if your crystal is damaged and try with replace it with other ECS-270-18-23A-EN and also try with ABM7-27.000MHZ-D2Y-T.

Other issue might be the oscillator PCB layout of your custom board, compare it with the DM816x TI EVM gerber files.

support.spectrumdigital.com/.../

Regards,
Pavel

Dear Pavel Botev,

The ECS-270-18-23A-EN is not damaged, it runs well when I take it to another board (not DM8168 board).

The oscillator PCB layout is also OK, there is only 3 nets for that.

With DM8168, there are 6 power rails need for power-up schedule. (3.3V, 1.8V_A, 1.8V_D, 1.5V, 1V_CON, 1V, 0.9V)

I have reworked one by one power block on new PCB board.

But the x-tal is still not run! So I can not check the ARM core and DSP core by JTAG.

Do you have any idea for debugging that problem?

Thank you very much!

Try with ABM7-27.000MHZ-D2Y-T crystal

I have tried ABM7-27.000MHZ-D2Y-T, but it also can not run.
I am afraid that the PLL block on chip does not run!

The 6 power supply voltage and sequence (follow datasheet) is OK
How can I check to know the chip and PLL block is power on?

Thanks!

How about the voltage at DEVOSC_VSS pin? With my board, the voltage is nearly ZERO.
I am reworking with new board, hope that everything is OK.

Thanks,

Cao Son Dinh said:

How about the voltage at DEVOSC_VSS pin? With my board, the voltage is nearly ZERO.

This is ground, so nearly ZERO looks fine.