Datasheet

Interfaces
60 Intel® Xeon® Processor E5-1600/E5-2600/E5-4600 v2 Product Families
Datasheet Volume One of Two
Note: Reads to caching agents that are not enabled will return all zeroes. Refer to the debug handbook for
details on methods to interpret the crash dump results using the Cbo TOR data shown in Figure 2-40.
2.5.2.6.31 Thermal Margin Read
This service allows the PECI host to read the margin to the processor thermal profile or
load line. Thermal margin data is returned in the format shown in Figure 2-41 with a
sign bit, an integer part and a fractional part. A negative thermal margin value implies
that the processor is operating in violation of its thermal load line and may be indicative
of a need for more aggressive cooling mechanisms through a fan speed increase or
other means. This PECI service will continue to return valid margin values even when
the processor die temperature exceeds T
Prochot
.
2.5.2.7 RdIAMSR()
The RdIAMSR() PECI command provides read access to Model Specific Registers
(MSRs) defined in the processor’s Intel® Architecture (IA). MSR definitions may be
found in the Intel® Xeon® Processor E5 v2 Product Family Processor Datasheet,
Volume Two: Registers. Refer to Table 2-11 for the exact listing of processor registers
accessible through this command.
2.5.2.7.1 Command Format
The RdIAMSR() format is as follows:
Write Length: 0x05
Read Length: 0x09 (qword)
Command: 0xb1
Description: Returns the data maintained in the processor IA MSR space as specified
by the ‘Processor ID’ and ‘MSR Address’ fields. The Read Length dictates the desired
data return size. This command supports only qword responses. All command
responses are prepended with a completion code that contains additional pass/fail
Figure 2-40. Caching Agent TOR Read Data
Read Mode (bit 11) = ‘0’ (within the Paramenter)
031
Cbo TOR Data
Read Mode (bit 11) = ‘1’ (within the Parameter)
RESERVED
031
Core ID
35
Valid
4
Figure 2-41. DTS Thermal Margin Read
Sign
Bit
14
RESERVED
16
Thermal Margin
(Integer Value)
61531
Thermal Margin
(Fractional Value)
5 0