Intel CM8062101038606, E5-4600 Originator Responses, DTS Temperature Data, Format, Interpretation

2.5.6Originator 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 Table 2-22for originator response guidelines.

Refer to the definition of each command in Section 2.5.2 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.

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	N/A
	attempts and notify
	application layer
None (all 0’s)	Force bus idle (drive	Fail with PECI client device error. Client may not be alive or may be
	low) for 1 mS and retry	otherwise unresponsive (for example, it could be in RESET).
CC: 0x4x	Pass	N/A
Good FCS	Pass	N/A

2.5.7DTS Temperature Data

2.5.7.1Format

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.

Figure 2-50. Temperature Sensor Data Format

MSB

MSB

LSB

LSB

Upper nibble

Lower nibble

Upper nibble

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)

2.5.7.2Interpretation

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 Figure 2-50. 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.

76	Intel® Xeon® Processor E5-1600/E5-2600/E5-4600 Product Families
	Datasheet Volume One