IBM Intel Xeon E5-2680 81Y5188 User Manual

Intel® Xeon® Processor E5-1600/E5-2600/E5-4600 Product Families

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Datasheet Volume One

In cases where the socket is not one Intel QPI hop away from the Firmware Agent 

socket, or a working link to the Firmware Agent socket cannot be resolved, the socket 

is placed in Link Init mode. The socket performs a minimal amount of internal 
configuration and waits for complete configuration by BIOS.

Availability of PECI services may be affected by the processor PECI client error status. 

Server manageability requirements place a strong emphasis on continued availability of 

PECI services to facilitate logging and debug of the error condition. 

• Most processor PECI client services are available in the event of a CAT_ERR_N 

assertion though they cannot be guaranteed.

• The Ping(), GetDIB(), GetTemp(), RdPkgConfig() and WrPkgConfig() commands will 

be serviced if the source of the CAT_ERR_N assertion is not in the processor power 
control unit hardware, firmware or associated register logic. Additionally, the 

RdPCIConfigLocal() and WrPCIConfigLocal() commands may also be serviced in this 

case.

• It is recommended that the PECI originator read Index 0/Parameter 5 using the 

RdPkgConfig() command to debug the CAT_ERR_N assertion. 

— The PECI client will return the 0x91 completion code if the CAT_ERR_N 

assertion is caused by the PCU hardware, firmware or associated logic errors. 

In such an event, only the Ping(), GetTemp() and GetDIB() PECI commands 

may be serviced. All other processor PECI services will be unavailable and 

further debug of the processor error status will not be possible.

— If the PECI client returns a passing completion code, the originator should use 

the response data to determine the cause of the CAT_ERR_N assertion. In such 

an event, it is also recommended that the PECI originator determine the exact 

suite of available PECI client services by issuing each of the PECI commands. 

The processor will issue ‘timeout’ responses for those services that may not be 

available.

— If the PECI client continues to return the 0x81 completion code in response to 

multiple retries of the RdPkgConfig() command, no PECI services, with the 

exception of the Ping(), GetTemp() and GetDIB(), will be guaranteed.

• The RdIAMSR() command may be serviced during a CAT_ERR_N assertion though it 

cannot be guaranteed.

The PECI originator may need to retry a command if the processor PECI client responds 
with a ‘response timeout’ completion code or a bad Read FCS. In each instance, the 

processor PECI client may have started the operation but not completed it yet. When 

the 'retry' bit is set, the PECI client will ignore a new request if it exactly matches a 
previous valid request.

The processor PECI client will not clear the semaphore that was acquired to service the 
request until the originator sends the ‘retry’ request in a timely fashion to successfully 

retrieve the response data. In the absence of any automatic timeouts, this could tie up 

shared resources and result in artificial bandwidth conflicts.