Datasheet
71
Thermal Specifications and Design Considerations
active/inactive transitions of the TCC when the processor temperature is near the trip
point. The duty cycle is factory configured and cannot be modified. Also, automatic
mode does not require any additional hardware, software drivers, or interrupt handling
routines. Processor performance will be decreased by the same amount as the duty
cycle when the TCC is active.
When TM2 is enabled and a high temperature situation exists, the processor will
perform an Enhanced Intel SpeedStep Technology transition to the LFM. When the
processor temperature drops below the critical level, the processor will make an
Enhanced Intel SpeedStep Technology transition to the last requested operating point.
The processor also supports Enhanced Multi-Threaded Thermal Monitoring (EMTTM).
EMTTM is a processor feature that enhances TM2 with a processor throttling algorithm
known as Adaptive TM2. Adaptive TM2 transitions to intermediate operating points,
rather than directly to the LFM, once the processor has reached its thermal limit and
subsequently searches for the highest possible operating point. Please ensure this
feature is enabled and supported in the BIOS. Also with EMTTM enabled, the operating
system can request the processor to throttling to any point between Intel
Dynamic Acceleration Technology frequency and SuperLFM frequency as long
as these features are enabled in the BIOS and supported by the processor.
The Intel Thermal Monitor automatic mode and Enhanced Multi-Threaded
Thermal Monitoring must be enabled through BIOS for the processor to be
operating within specifications. Intel recommends TM1 and TM2 be enabled on the
processors.
TM1, TM2 and EMTTM features are collectively referred to as Adaptive Thermal
Monitoring features.
TM1 and TM2 can co-exist within the processor. If both TM1 and TM2 bits are enabled in
the auto-throttle MSR, TM2 takes precedence over TM1. However, if Force TM1 over
TM2 is enabled in MSRs via BIOS and TM2 is not sufficient to cool the processor below
the maximum operating temperature, then TM1 will also activate to help cool down the
processor.
If a processor load-based Enhanced Intel SpeedStep Technology transition (through
MSR write) is initiated when a TM2 period is active, there are two possible results:
1. If the processor load-based Enhanced Intel SpeedStep Technology transition target
frequency is higher than the TM2 transition-based target frequency, the processor
load-based transition will be deferred until the TM2 event has been completed.
2. If the processor load-based Enhanced Intel SpeedStep Technology transition target
frequency is lower than the TM2 transition-based target frequency, the processor
will transition to the processor load-based Enhanced Intel SpeedStep Technology
target frequency point.
The TCC may also be activated via on-demand mode. If bit 4 of the ACPI Intel Thermal
Monitor control register is written to a 1, the TCC will be activated immediately
independent of the processor temperature. When using on-demand mode to activate
the TCC, the duty cycle of the clock modulation is programmable via bits 3:1 of the
same ACPI Intel Thermal Monitor control register. In automatic mode, the duty cycle is
fixed at 50% on, 50% off, however 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 at the same time automatic mode is enabled, however,
if the system tries to enable the TCC via on-demand mode at the same time automatic
mode is enabled and a high temperature condition exists, automatic mode will take
precedence.
An external signal, PROCHOT# (processor hot) is asserted when the processor detects
that its temperature is above the thermal trip point. Bus snooping and interrupt
latching are also active while the TCC is active.
Summary of Contents for BX80532PG3200D
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