IBM Intel Xeon E5606 49Y3776 User Manual
Product codes
49Y3776
Thermal Specifications
158
Intel
®
Xeon
®
Processor 5600 Series Datasheet Volume 1
PECI temperature readings are not reliable at temperatures above TCC activation (since
the processor is operating out of spec at this temperature). Therefore, the readings are
never positive.
the processor is operating out of spec at this temperature). Therefore, the readings are
never positive.
7.3.6.3
Temperature Filtering
The processor digital thermal sensor (DTS) provides an improved capability to monitor
device hot spots, which inherently leads to more varying temperature readings over
short time intervals. Coupled with the fact that typical fan speed controllers may only
read temperatures at 4 Hz, it is necessary for the thermal readings to reflect thermal
trends and not instantaneous readings. Therefore, PECI supports a configurable low-
pass temperature filtering function. By default, this filter results in a thermal reading
that is a moving average of 256 samples taken at approximately 1msec intervals. This
filter’s depth, or smoothing factor, may be configured to between 1 sample and 1024
samples, in powers of 2. See the equation below for reference where the configurable
variable is ‘X’.
device hot spots, which inherently leads to more varying temperature readings over
short time intervals. Coupled with the fact that typical fan speed controllers may only
read temperatures at 4 Hz, it is necessary for the thermal readings to reflect thermal
trends and not instantaneous readings. Therefore, PECI supports a configurable low-
pass temperature filtering function. By default, this filter results in a thermal reading
that is a moving average of 256 samples taken at approximately 1msec intervals. This
filter’s depth, or smoothing factor, may be configured to between 1 sample and 1024
samples, in powers of 2. See the equation below for reference where the configurable
variable is ‘X’.
T
N
= T
N-1
+ 1/2
X
* (T
SAMPLE
- T
N-1
)
7.3.6.4
Reserved Values
Several values well out of the operational range are reserved to signal temperature
sensor errors. These are summarized in the table below:
sensor errors. These are summarized in the table below:
7.3.7
Client Management
7.3.7.1
Power-Up Sequencing
The PECI client is fully reset during processor RESET# assertion. This means that any
transactions on the bus will be completely ignored, and the host will read the response
from the client as all zeroes. After processor RESET# deassertion, the Intel Xeon
processor 5600 series PECI client is operational enough to participate in timing
negotiations and respond with reasonable data. However, the client data is not
guaranteed to be fully populated until approximately 500 µs after processor RESET# is
deasserted. Until that time, the client responses to each command are as follows:
transactions on the bus will be completely ignored, and the host will read the response
from the client as all zeroes. After processor RESET# deassertion, the Intel Xeon
processor 5600 series PECI client is operational enough to participate in timing
negotiations and respond with reasonable data. However, the client data is not
guaranteed to be fully populated until approximately 500 µs after processor RESET# is
deasserted. Until that time, the client responses to each command are as follows:
Table 7-36. Error Codes and Descriptions
Error Code
Description
0x8000
General Sensor Error (GSE)
Table 7-37. PECI Client Response During Power-Up (During ‘Data Not Ready’)
Command
Response
Ping()
Fully functional
GetDIB()
Fully functional
GetTemp()
Client responds with a ‘hot’ reading, or 0x0000
PCIConfigRd()
Fully functional
PCIConfigWr()
Fully functional
MbxSend()
Fully functional
MbxGet()
Client responds with Abort FCS (if MbxSend() has been previously issued)