Intel L3426 BV80605004737AA Data Sheet

Product codes
BV80605004737AA
Page of 102
Thermal Specifications and Design Considerations
82
Dual-Core Intel® Xeon® Processor 3000 Series Datasheet
voltage transition back to the normal system operating point. Transition of the VID code 
will occur first, to insure proper operation once the processor reaches its normal 
operating frequency. Refer to 
 for an illustration of this ordering.
The PROCHOT# signal is asserted when a high temperature situation is detected, 
regardless of whether Thermal Monitor or Thermal Monitor 2 is enabled.
It should be noted that the Thermal Monitor 2 TCC cannot be activated via the on 
demand mode. The Thermal Monitor TCC, however, can be activated through the use of 
the on demand mode.
5.2.3
On-Demand Mode
The processor provides an auxiliary mechanism that allows system software to force 
the processor to reduce its power consumption. This mechanism is referred to as “On-
Demand” mode and is distinct from the Thermal Monitor feature. On-Demand mode is 
intended as a means to reduce system level power consumption. Systems using the 
processor must not rely on software usage of this mechanism to limit the processor 
temperature.
The processor provides an auxiliary mechanism that allows system software to force 
the processor to reduce its power consumption. This mechanism is referred to as 
“On-Demand” mode and is distinct from the Thermal Monitor and Thermal Monitor 2 
features. On-Demand mode is intended as a means to reduce system level power 
consumption. Systems must not rely on software usage of this mechanism to limit the 
processor temperature. If bit 4 of the IA32_CLOCK_MODULATION MSR is set to a 1, the 
processor will immediately reduce its power consumption via modulation (starting and 
stopping) of the internal core clock, independent of the processor temperature. When 
using On-Demand mode, the duty cycle of the clock modulation is programmable via 
bits 3:1 of the same IA32_CLOCK_MODULATION MSR. In On-Demand mode, the duty 
cycle can be programmed from 12.5% on/ 87.5% off to 87.5% on/ 12.5% off in 12.5% 
increments. On-Demand mode may be used in conjunction with the Thermal Monitor; 
Figure 5-5. Thermal Monitor 2 Frequency and Voltage Ordering
VID
Frequency
Temperature
T
TM2
f
MAX
f
TM2
VID
VID
TM2
PROCHOT#