
Features
6-12
Intel Xeon Processor MP with up to 2MB L3 Cache
will clear any alarm bits that may have been set, unless the alarm condition persists. If the
SM_ALERT# signal is enabled via the Thermal Sensor Configuration Register and a thermal diode
threshold is exceeded, an alert will be sent to the platform via the SM_ALERT# signal.
This register is read by accessing the RS Command Register.
6.4.6.4
Configuration Register
The Configuration Register controls the operating mode (stand-by vs. auto-convert) of the SMBus
thermal sensor.
Table 46 shows the format of the Configuration Register. If the RUN/STOP bit is
set (high) then the thermal sensor immediately stops converting and enters stand-by mode. The
thermal sensor will still perform analog to digital conversions in stand-by mode when it receives a
one-shot command. If the RUN/STOP bit is clear (low) then the thermal sensor enters auto-
conversion mode.
This register is accessed by using the thermal sensor Command Register: The RC command
register is used for read commands and the WC command register is used for write commands. See
Table 45. SMBus Thermal Sensor Status Register
Bit
Name
Reset State
Function
7 (MSB)
BUSY
N/A
If set, indicates that the device’s analog to digital converter is
busy.
6
RESERVED
Reserved for future use
5
RESERVED
Reserved for future use
4
RHIGH
0
If set, indicates the processor core thermal diode high
temperature alarm has activated.
3RLOW
0
If set, indicates the processor core thermal diode low
temperature alarm has activated.
2
OPEN
0
If set, indicates an open fault in the connection to the
processor core diode.
1
RESERVED
Reserved for future use.
0 (LSB)
RESERVED
Reserved for future use.
Table 46. SMBus Thermal Sensor Configuration Register
Bit
Name
Reset State
Function
7 (MSB)
MASK
0
Mask SM_ALERT# bit. Clear bit to allow interrupts via
SM_ALERT# and allow the thermal sensor to respond to the
ARA command when an alarm is active. Set the bit to disable
interrupt mode. The bit is not used to clear the state of the
SM_ALERT# output. An ARA command may not be
recognized if the mask is enabled.
6
RUN/STOP
0
Stand-by mode control bit. If set, the device immediately stops
converting, and enters stand-by mode. If cleared, the device
converts in either one-shot mode or automatically updates on
a timed basis.
5:0
RESERVED
Reserved for future use.