XIO2001: used in -40 temp

Hi Shu-Cheng,

What do you mean by "the PCIe cannot be turned on"? Do you mean the computer cannot recognize the XIO2001?

Yes, there is a power-up sequence that needs to be followed. It is on page 22 of the datasheet.

Regards,

I.K. 

Hi Sirs,

Thanks for your reply,

It's mean our system will to detect all interface (like PCI-E, USB, PCI...) when turn on,

But if the system to detect the PCI on -30 to -40 degrees, the system will be hold , Need to disable PCI on bios mode then system could be work.

So is it because power sequenice to affect? but why didn't happen on 25 degrees?

Hi Sirs,

Sorry to pushed, have any update on here?

Thanks!!

Hi Sirs,

We found a problem while confirming the timing.
At present, the signal of GRST of XIO2001 is followed by the power of VDD_33_AUS.
Therefore, it will not fall behind 3.3V & 1.5V as in the timing chart.
Can you please help me to confirm if this behavior is correct?

Thank you

Hi Shu-Cheng,

As in the timing chart, GRST# should only be deasserted after all of the 3.3V/1.5V power is stable high. Are you saying that GRST# is being deasserted before the 3.3V/1.5V power is stable high? 

Regards,

I.K.

Hi sir

I am Eric,the person in charge of this project.

According to your description,VDD_33_AUX and VDD_33 should be the same power rails.
Is this understanding correct?

The current design VDD_33_AUX will be about 650mS earlier than VDD_33.
Is this the main reason why system can't be boot up?
If yes, why is it different under different temperature conditions?

Can you give us some help with this question?
Thank you

Eric

Hi I.K,

Thanks for your reply.

Actually the power sequence are same whatever the IC is on 25 degree or -40 degree, but why fail phenomenon only on -40 degree?

It should be fine if VDD_33_AUX comes up a little bit earlier than VDD_33, but VDD_33, VDDA_33, VDD_15, VDDA_15, and PCIR should all be up and stable before GRST# is deasserted. You should always follow the datasheet required power up sequences as failures related to these can be marginal and difficult to interpret. 

Please post an oscilloscope screenshot of the power up sequence of your system (similar to that of Figure 4).  

Regards,

I.K. 

Hi sir

The following are the waveforms at different temp.

I didn't find any difference.

Thank you

Hi Sirs,

Sorry to pushed, have any idea on our waveform?