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C620 Series GPIO

mrydhan
Beginner
360 Views

I am unable to find the GPIO Base address for the C620 series GPIOs. In the other PCHs the GPIO are part of PCI bus D31:F0. But I can't find this on the C620 series data sheet. I need to know what the base address and where can I find it?

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11 Replies
JoseH_Intel
Moderator
306 Views

Hello mrydhan,


Thank you for joining the Intel community


Have you already look at the Signal Description in the Section 18 GPIO from the following data sheet: 

https://www.intel.la/content/dam/www/public/us/en/documents/datasheets/c620-series-chipset-datasheet...


In table 18-3 (section 18.6) the very first line is for the base address. Is that whar you are looking for?

https://www.intel.la/content/dam/www/public/us/en/documents/datasheets/c620-series-chipset-datasheet...


If not please let me know so I can do further research


Regards


Jose A.

Intel Customer Support Technician

For firmware updates and troubleshooting tips, visit:

https://intel.com/support/serverbios


mrydhan
Beginner
303 Views

Hi Jose,

Thanks for your reply.

Actually what I need is the Base address for accessing these GPIO registers. From my further googling I found out that the base address is is located in P2SB (Primary to Sideband) Section 36.9. This is a hidden PCH private configuration space in D31:F1. Unfortunately, it is hidden by the BIOS.

The base address of the Private Configuration Space is hidden. It resides inside one of the base address registers of a PCI device, D31:F1 (P2SB Bridge), but this device is hidden by the BIOS. However, the hiding mechanism only blocks reads. In order to unhide it, a zero must be written to the 8th bit of offset 0xE0 (P2SBC, P2SB Control) of D31:F1; after this, the device is readable again. From there, the base address of the PCR can be read out from the first BAR of the device. 

The question now is how to write bit 8 offset 0xE0 of D31:F1. 

Regards,

JoseH_Intel
Moderator
301 Views

Hello mrydhan,


Thank you for the clarification. Please allow me a bit of time in order to research on this and I will get back to you as soon as I have any updates.


Regards


Jose A.

Intel Customer Support Technician

For firmware updates and troubleshooting tips, visit:

https://intel.com/support/serverbios


JoseH_Intel
Moderator
298 Views

Hello mrydhan,


Could you please attach the board manufacturer and model.


We will look forward for your updates.


Regards


Jose A.

Intel Customer Support Technician

For firmware updates and troubleshooting tips, visit:

https://intel.com/support/serverbios


mrydhan
Beginner
293 Views

This is non commercial Motherboard. 

JoseH_Intel
Moderator
289 Views

Hello mrydhan,


Is it like a prototype design based on C620 chipset? Are you designing a custom BIOS image?


Jose A.

Intel Customer Support Technician

For firmware updates and troubleshooting tips, visit:

https://intel.com/support/serverbios


mrydhan
Beginner
287 Views

No it is not a prototype design. It is a white-box ODM design. The design is not the problem.

By default these BIOS are "hiding" this specific register (P2SB). This is from searching online. 

BIOS is AMI Aptio V based BIOS. 

When I posted this query on this forum, I did was not aware of these details. 

I think there a way to write to bit 8 P2SB Control Register at offset 0xE0 to unhide. But because this register is hidden read from this register just returns all FFs. But supposedly write is not affected. So the question is how to actually write? There is setpci command to write PCI configuration space. But at this moment I am not sure if writing could cause some unintended effects.

So if can figure out how to use setpci command with C600 series P2SB Control register that would be great. I am uisng Linux.

On-line searches provide some results but those are for older Intel PCHs. 

Regards,

JoseH_Intel
Moderator
284 Views

Hello mrydhan,


Thank you for the update. Will get back to you shortly.


Jose A.

Intel Customer Support Technician

For firmware updates and troubleshooting tips, visit:

https://intel.com/support/serverbios


JoseH_Intel
Moderator
271 Views

Hello mrydhan,


I am sorry to keep insisting on this. We need to confirm the model of your board since we usually do not provide support for Server chipsets. In such case if your board is OEM you may need to go to them for support. If you have an Intel board we can evaluate your request. Please let us know your feedback.


Regards


Jose A.

Intel Customer Support Technician

For firmware updates and troubleshooting tips, visit:

https://intel.com/support/serverbios


mrydhan
Beginner
267 Views

As I mentioned in the previous response, it is not commercially available board.

NO problem I will try to work with the vendor directly. 

Thanks for your support.

JoseH_Intel
Moderator
264 Views

Hello mrydhan,


I really apologize for not been more helpful. We will proceed to mark this thread as closed. If you have further issues or questions just go ahead and submit a new topic.


Regards


Jose A.

Intel Customer Support Technician

For firmware updates and troubleshooting tips, visit:

https://intel.com/support/serverbios


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