Intel AT80604004881AA User Manual

124

Intel® Xeon® Processor 7500 Datasheet, Volume 1

1.

Refer to 

 for a summary of mailbox commands supported by the Intel® Xeon® processor 7500 

series CPU.

The Intel® Xeon® processor 7500 series PECI client is designed to support the 
following sideband functions:

• Processor and DRAM thermal management
• Platform manageability functions, including thermal, power and electrical error 

monitoring

• Processor interface tuning and diagnostics capabilities (Intel

®

 Interconnect BIST 

(Intel

®

 IBIST)).

Processor fan speed control is managed by comparing PECI thermal readings against 
the processor-specific fan speed control reference point, or T

CONTROL

. Both T

CONTROL

 

and PECI thermal readings are accessible via the processor PECI client. These variables 
are referenced to a common temperature, the TCC activation point, and are both 
defined as negative offsets from that reference. Algorithms for fan speed management 
using PECI thermal readings and the T

CONTROL

 reference are documented in 

PECI-based access to DRAM thermal readings and throttling control coefficients provide 
a means for Board Management Controllers (BMCs) or other platform management 
devices to feed hints into on-die memory controller throttling algorithms. These control 
coefficients are accessible using PCI configuration space writes via PECI. The PECI-
based configuration write functionality is defined in 

.

PECI allows full read access to error and status monitoring registers within the 
processor’s PCI configuration space. It also provides insight into thermal monitoring 
functions such as TCC activation timers and thermal error logs.

Ping()

Yes

GetDIB()

Yes

GetTemp()

Yes

PCIConfigRd()

Yes

PCIConfigWr()

Yes

MbxSend()

 1

Yes

MbxGet() 

1

Yes