Datasheet

Interfaces
Intel
®
Xeon
®
Processor C5500/C3500 Series
Datasheet, Volume 1 February 2010
78 Order Number: 323103-001
2.2.2.6.1 Capabilities
Any MbxSend request with a request type not defined in Table 34 will result in a failing
completion code.
More detailed command definitions follow.
2.2.2.6.2 Ping
The Mailbox interface may be checked by issuing a Mailbox ‘Ping’ command. If the
command returns a passing completion code, it is functional. Under normal operating
conditions, the Mailbox Ping command should always pass.
2.2.2.6.3 Thermal Status Read / Clear
The Thermal Status Read provides information on package level thermal status. Data
includes:
• The status of TCC activation
• Bidirectional PROCHOT# assertion
•Critical Temperature
Table 34. Mailbox Command Summary
Command
Name
Request
Type
Code
(byte)
MbxSend
Data
(dword)
MbxGet Data
(dword)
Description
Ping 0x00 0x00 0x00 Verify the operability / existence of the mailbox.
Thermal Status
Read/Clear
0x01 Log bit clear
mask
Thermal
Status
Register
Read the thermal status register and optionally clear any log bits.
The thermal status has status and log bits indicating the state of
processor TCC activation, external PROCHOT# assertion, and
Critical Temperature threshold crossings.
Counter
Snapshot
0x03 0x00 0x00 Snapshots all PECI-based counters
Counter Clear 0x04 0x00 0x00 Concurrently clear and restart all counters.
Counter Read 0x05 Counter
Number
Counter Data Returns the counter number requested.
0: Total reference time
1: Total TCC Activation time counter
Icc-TDC Read 0x06 0x00 Icc-TDC Returns the specified Icc-TDC of this part, in Amps.
Thermal Config
Data Read
0x07 0x00 Thermal
config data
Reads the thermal averaging constant.
Thermal Config
Data Write
0x08 Thermal
Config Data
0x00 Writes the thermal averaging constant.
Tcontrol Read 0x09 0x00 Tcontrol Reads the fan speed control reference temperature, Tcontrol, in
PECI temperature format.
Machine Check
Read
0x0A Bank
Number /
Index
Register Data Read CPU Machine Check Banks.
T-state
Throttling
Control Read
0xB 0x00 ACPI T-state
Control Word
Reads the PECI ACPI T-state throttling control word.
T-state
Throttling
Control Write
0xC ACPI T-
state
Control
Word
0x00 Writes the PECI ACPI T-state throttling control word.