IBM Intel Xeon E5606 81Y5943 User Manual
Product codes
81Y5943
Thermal Specifications
138
Intel
®
Xeon
®
Processor 5600 Series Datasheet Volume 1
7.3.2.3
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. Note that 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
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. Note that 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
), or using a RDMSR instruction.
7.3.2.3.1
Command Format
The GetTemp() format is as follows:
Write Length: 1
Read Length: 2
Command: 0x01
Multi-Domain Support: Yes (see
Description: Returns the current temperature for addressed processor PECI client.
Example bus transaction for a thermal sensor device located at address 0x30 returning
a value of negative 10° C:
a value of negative 10° C:
7.3.2.3.2
Supported Responses
The typical client response is a passing FCS and good thermal data. Under some
conditions, the client’s response will indicate a failure.
conditions, the client’s response will indicate a failure.
Figure 7-18. GetTemp()
Byte #
Byte
Definition
0
Client Address
1
Write Length
0x01
2
Read Length
0x02
4
FCS
5
Temp[7:0]
6
Temp[15:8]
7
FCS
3
Cmd Code
0x01
Figure 7-19. GetTemp() Example
Byte #
Byte
Definition
0
0x30
1
0x01
2
0x02
4
0xef
5
0x80
6
0xfd
7
0x4b
3
0x01