NEC Intel Xeon E5-2420 N8101-571F User Manual

Product codes
N8101-571F
Page of 258
76
Intel® Xeon® Processor E5-1600/E5-2600/E5-4600 Product Families
Datasheet Volume One
2.5.6
Originator Responses
The simplest policy that an originator may employ in response to receipt of a failing 
completion code is to retry the request. However, certain completion codes or FCS 
responses are indicative of an error in command encoding and a retry will not result in 
a different response from the client. Furthermore, the message originator must have a 
response policy in the event of successive failure responses. Refer to 
 fo
originator response guidelines.
Refer to the definition of each command in 
 for a specific definition of 
possible command codes or FCS responses for a given command. The following 
response policy definition is generic, and more advanced response policies may be 
employed at the discretion of the originator developer.
2.5.7
DTS Temperature Data
2.5.7.1
Format
The temperature is formatted in a 16-bit, 2’s complement value representing a number 
of 1/64 degrees centigrade. This format allows temperatures in a range of ±512° C to 
be reported to approximately a 0.016° C resolution.
2.5.7.2
Interpretation
The resolution of the processor’s Digital Thermal Sensor (DTS) is approximately 1°C, 
which can be confirmed by a RDMSR from the IA32_THERM_STATUS MSR where it is 
architecturally defined. The MSR read will return only bits [13:6] of the PECI 
temperature sensor data defined in 
. PECI temperatures are sent through a 
configurable low-pass filter prior to delivery in the GetTemp() response data. The 
output of this filter produces temperatures at the full 1/64°C resolution even though 
the DTS itself is not this accurate.
Table 2-23. Originator Response Guidelines
Response
After 1 Attempt
After 3 Attempts
Bad FCS
Retry
Fail with PECI client device error.
Abort FCS
Retry
Fail with PECI client device error if command was not illegal or 
malformed.
CC: 0x8x
Retry
The PECI client has failed in its attempts to generate a response. 
Notify application layer.
CC: 0x9x
Abandon any further 
attempts and notify 
application layer
N/A
None (all 0’s)
Force bus idle (drive 
low) for 1 mS and retry
Fail with PECI client device error. Client may not be alive or may be 
otherwise unresponsive (for example, it could be in RESET).
CC: 0x4x
Pass
N/A
Good FCS
Pass
N/A
Figure 2-50. Temperature Sensor Data Format
MSB
Upper nibble
MSB
Lower nibble
LSB
Upper nibble
LSB
Lower nibble
S
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
Sign
Integer Value (0-511)
Fractional Value (~0.016)