Datasheet

Intel

Xeon

Processor C5500/C3500 Series

February 2010 Datasheet, Volume 1

Order Number: 323103-001 73

Interfaces

2.2.2.2.3 Revision Number

All clients that support the GetDIB command also support Revision Number reporting.

The revision number may be used by a host or originator to manage different command

suites or response codes from the client. Revision Number is always reported in the

second byte of the GetDIB() response. The Revision Number always maps to the

revision number of the supported PECI Specification.

For a client that is designed to meet the Revision 2.0 RS - Platform Environment

Control Interface (PECI) Specification, the Revision Number it returns will be ‘0010

0000b’.

2.2.2.3 GetTemp()

The GetTemp() command is used to retrieve the temperature from a target PECI

address. The temperature is used by the external thermal management system to

regulate the temperature on the die. The data is returned as a negative value

representing the number of degrees centigrade below the Thermal Control Circuit

Activation temperature of the PECI device. A value of zero represents the temperature

at which the Thermal Control Circuit activates. The actual value that the thermal

management system uses as a control set point (Tcontrol) is also defined as a negative

number below the Thermal Control Circuit Activation temperature. TCONTROL may be

extracted from the processor by issuing a PECI Mailbox MbxGet() (see Section 2.2.2.8),

or using a RDMSR instruction.

See Section 2.2.6 for details regarding temperature data formatting.

2.2.2.3.1 Command Format

The GetTemp() format is as follows:

Write Length: 1

Read Length: 2

Command: 0x01

Multi-Domain Support: Yes (see Table 41)

Description: Returns the current temperature for addressed processor PECI client.

Figure 16. Revision Number Definition

Major Revision#

Minor Revision#