Elkhart Lake. G3-> S5/S4. PMC_SLP_S4# not going high

[KVN]

Hi!

I am trying to power up Elkhart Lake x6427FE.
G3 to S5 going ok with SUSn and SUSCLK signal are appearing as it should be. However SLP_S5 did not go high.

After PWRBTN_N go low SLP_S3  and SLP_S4 signals are not going to high as well.

Please advise.

I attached Oscilloscope screenshot

[Diego_INTEL]

Hello @KVN,

Thank you for contacting Intel Embedded Community.

Please check the following documents:

Document #730333 - Board Bring Up Debug Cookbook - User Guide

Section 3.5 - List of Common Boot/Hang Issues on Intel Atom®/Client Product

Document #599710 - PDG

Section 29.3 - Platform Power Sequencing Specification 

You will need a Premier account in order to get access to the documentation.

https://www.intel.com/content/www/us/en/support/articles/000058073/programs/resource-and-documentation-center.html

Best regards,

@Diego_INTEL 

[KVN]

Hello Diego,

Thank you for your reply.

I have checked documents you mentioned.

I have following questions:
1) From 730333 document it is look like BIOS should be upload to go to S4 -> S0 states?

2) Also, can it be that SLP_S5 is not going high because there is no BIOS in FLASH memory? At the moment only SUSn and SUSCLK going high and I can see that CPU is trying to read data from Flash

[KVN]

Hello Diego,

We uploaded BIOS and CPU went to S0 state for a few seconds and then it is going to S5.

I checked THERMTRIPn signal and it is not changing.

I can push PWRBTNn signal to zero and CPU is going to S0 state for a few seconds again.
1) What reasons can be?

2) Can BIOS affect that?

3) GP21/SIO_UART2 and GP20/SIO_UART2 configured as atlernative 4 function but we do not see any logs there?

Will BIOS send his logs to SIO_UART2?

Thank you

[Diego_INTEL]

Hello @KVN,

I will try to check more regarding this.

Could you compare the Power Sequence with the PDG?

Best regards,

@Diego_INTEL 

[KVN]

Hi Diego and Venua,

We checked CAT_ERR# signal and it was go low after PLTRST# signal

It is hard to find in Intel Documentation why it could happen. It is said that some sensor error appeared...

Only in debug cookbook, last line was that VBOOT need to be checked.

VBOOT is value of VCCIN power by default

We used TPS544C26 for VCCIN and VBOOT is 1.1V there. It should be 1.8V when it starts.

We changed via I2C and it BIOS went further and start to send data to terminal finally

[KVN]

Hi Diego!

Update.

CPU switching on and goes to S0 state. PLTRSTn and PCH_PWROK signals going up.

Then ALWAYS after 22 seconds it goes to S5 state(SLP_S3 and SLP_S4 signals going down) for a few seconds. Then it is starting again(SLP_S4,SLP_S3 signals going up) for another 22 seconds and then again off. 

BIOS definitely read by CPU(We checked and decode communication between CPU and NOR FLASH(BIOS) )

So, we can see that power sequencing and BIOS read last for approximately 2 seconds. Then nothing happen(Power ON) for another 20 seconds(Always same time) then CPU or PCH pushing system to state S5. 

SLP_S3 ALWAYS going down first, then SLP_S4. 

I checked all power rails before SLP_S3 going down and they all OK and not changing until SLP_S3 going down

We also checked interface SVID(CLK, DATA and ALERT) for any communication with VCCIN power converter - No communication

We dont see any logs on SIO_UART2 terminal as well

Also, I can confirm that THERMTRIPn signal is not going low as well

1)What can cause CPU to go from S0 to S5 and back?

2) Can BIOS cause that? 

3) What else can we checked?

I attached power on sequence and critical time pictures from oscilloscope according to 621478_Elkhart_Lake_Power_Up_Checklist Rev2.

[KVN]

More pictures

[Venua]

Hi KVN,

Do you have any updates on your issue? Does the boot up issue solved on your board?

Can you see SVID transition after PLTRST_N?

[KVN]

Hi Venua,

Nope no SVID communication after PLTRST_N

[Venua]

Hi KVN,

Have you verified the hardstraps & softstraps as per the EDS.

[Venua]

Dear KVN,

Have you verified DocID#599710, EHL PDG and EDS documents for Hard and Soft straps.

Is your problem solved, are you able to boot the complete board now?

Are you still getting Thermal trip signal.