Reading a MCHBAR register within the processor; what's the base address?

[AAhusk]

I am trying to read DIMM temperature values from a register within the processor.

According to the datasheet 6th Gen Intel Core/Pentium/Celeron/Xeon Processors EDS, Volume 2 (https://cdrdv2.intel.com/v1/dl/getcontent/334408), there is a DDR register with offset 58B4h that reads the Per-DIMM temperature values. It is located on Bus 0, Device 0, and Function 0. It is within the MCHBAR registers section of the datasheet. 

So, I have the Bus, Device, Function, and Offset of this register but I was struggling to find the base address of this.

In section 3.12 I found the "Host Memory Mapped Register Range Base(MCHBAR)" with offset 48h. It says that bits 38:15 correspond to the "base address Host Memory Mapped configuration space"; so I was thinking that reading bits 38:15 would give me the base address for all the MCHBAR registers. Is that correct?

When I read bits 38:15, I get 0x1FDA2, and I try using it with the offset 0x58B4, but only read a value of 0, so I'm thinking I'm doing something wrong.

I am using a software library with a method that takes in Bus, Device, Function, Base Address, and Offset to read registers in the PCI space, so I am assuming I simply having something wrong with the address.

[Esteban_D_Intel]

Hello AAhusk,

Thank you for posting on the Intel® communities.  

After checking the description, I would like to inform you that we have a specific forum to answer all of your concerns.

Please post you question under the following topic:

https://community.intel.com/t5/Software-Tuning-Performance/bd-p/software-tuning-perf-optimization

Additionally, I would recommend checking the Developer’s Manual in the following link.

In that way you will get specialized support on this matter.

I hope you find this helpful.

If you need any additional information, please submit a new question as this thread will no longer being monitored  

Esteban D.

Intel Technical Support Technician