Intel E5-1600, E5-4600 Client Command Suite, Thermal Management, Platform Manageability, Ping

2.5.1.1Thermal Management

Processor fan speed control is managed by comparing Digital Thermal Sensor (DTS) thermal readings acquired via PECI against the processor-specific fan speed control reference point, or TCONTROL. Both TCONTROL and DTS thermal readings are accessible via the processor PECI client. These variables are referenced to a common temperature, the TCC activation point, and are both defined as negative offsets from that reference.

PECI-based access to the processor package configuration space provides a means for Baseboard Management Controllers (BMCs) or other platform management devices to actively manage the processor and memory power and thermal features. Details on the list of available power and thermal optimization services can be found in

Section 2.5.2.6.

2.5.1.2Platform Manageability

PECI allows read access to certain error registers in the processor MSR space and status monitoring registers in the PCI configuration space within the processor and downstream devices. Details are covered in subsequent sections.

PECI permits writes to certain Memory Controller RAS-related registers in the processor PCI configuration space. Details are covered in Section 2.5.2.10.

2.5.1.3Processor Interface Tuning and Diagnostics

The processor Intel® Interconnect Built In Self Test (Intel® IBIST) allows for in-field diagnostic capabilities in the Intel® QPI and memory controller interfaces. PECI provides a port to execute these diagnostics via its PCI Configuration read and write capabilities in the BMC INIT mode. Refer to Section 2.5.3.7 for more details.

2.5.2Client Command Suite

PECI command requires at least one frame check sequence (FCS) byte to ensure reliable data exchange between originator and client. The PECI message protocol defines two FCS bytes that are returned by the client to the message originator. The first FCS byte covers the client address byte, the Read and Write Length bytes, and all bytes in the write data block. The second FCS byte covers the read response data returned by the PECI client. The FCS byte is the result of a cyclic redundancy check (CRC) of each data block.

2.5.2.1Ping()

Ping() is a required message for all PECI devices. This message is used to enumerate devices or determine if a device has been removed, been powered-off, etc. A Ping() sent to a device address always returns a non-zero Write FCS if the device at the targeted address is able to respond.

2.5.2.1.1Command Format

The Ping() format is as follows: Write Length: 0x00

Read Length: 0x00

Intel® Xeon® Processor E5-1600/E5-2600/E5-4600 Product Families	31
Datasheet Volume One