Intel D525 AU80610006225AA Manuale Utente
Codici prodotto
AU80610006225AA
Datasheet
61
Thermal Specifications and Design Considerations
When calculating a temperature based on the thermal diode measurements, a number
of parameters must be either measured or assumed. Most devices measure the diode
ideality and assume a series resistance and ideality trim value, although are capable of
also measuring the series resistance. Calculating the temperature is then accomplished
using the equations listed under
of parameters must be either measured or assumed. Most devices measure the diode
ideality and assume a series resistance and ideality trim value, although are capable of
also measuring the series resistance. Calculating the temperature is then accomplished
using the equations listed under
. In most sensing devices, an expected
value for the diode ideality is designed-in to the temperature calculation equation. If
the designer of the temperature sensing device assumes a perfect diode, the ideality
value (also called n
the designer of the temperature sensing device assumes a perfect diode, the ideality
value (also called n
trim
) will be 1.000. Given that most diodes are not perfect, the
designers usually select an n
trim
value that more closely matches the behavior of the
diodes in the processor. If the processor diode ideality deviates from that of the n
trim
,
each calculated temperature will be offset by a fixed amount. This temperature offset
can be calculated with the equation:
can be calculated with the equation:
T
error(nf)
= T
measured
* (1 - n
actual
/n
trim
)
where T
error(nf)
is the offset in degrees C, T
measured
is in Kelvin, n
actual
is the
measured ideality of the diode, and n
trim
is the diode ideality assumed by the
temperature sensing device.
7.1.2
Intel® Thermal Monitor
The Intel Thermal Monitor helps control the processor temperature by activating the
TCC (Thermal Control Circuit) when the processor silicon reaches its maximum
operating temperature. The temperature at which the Intel Thermal Monitor activates
the TCC is not user configurable. Bus traffic is snooped in the normal manner and
interrupt requests are latched (and serviced during the time that the clocks are on)
while the TCC is active.
TCC (Thermal Control Circuit) when the processor silicon reaches its maximum
operating temperature. The temperature at which the Intel Thermal Monitor activates
the TCC is not user configurable. Bus traffic is snooped in the normal manner and
interrupt requests are latched (and serviced during the time that the clocks are on)
while the TCC is active.
With a properly designed and characterized thermal solution, it is anticipated that the
TCC would only be activated for very short periods of time when running the most
power intensive applications. The processor performance impact due to these brief
periods of TCC activation is expected to be minor and hence not detectable. An under-
designed thermal solution that is not able to prevent excessive activation of the TCC in
the anticipated ambient environment may cause a noticeable performance loss and
may affect the long-term reliability of the processor. In addition, a thermal solution that
is significantly under designed may not be capable of cooling the processor even when
the TCC is active continuously.
TCC would only be activated for very short periods of time when running the most
power intensive applications. The processor performance impact due to these brief
periods of TCC activation is expected to be minor and hence not detectable. An under-
designed thermal solution that is not able to prevent excessive activation of the TCC in
the anticipated ambient environment may cause a noticeable performance loss and
may affect the long-term reliability of the processor. In addition, a thermal solution that
is significantly under designed may not be capable of cooling the processor even when
the TCC is active continuously.
The Intel Thermal Monitor controls the processor temperature by modulating (starting
and stopping) the processor core clocks when the processor silicon reaches its
maximum operating temperature. The Intel Thermal Monitor uses two modes to
activate the TCC: automatic mode and on-demand mode. If both modes are activated,
automatic mode takes precedence.
and stopping) the processor core clocks when the processor silicon reaches its
maximum operating temperature. The Intel Thermal Monitor uses two modes to
activate the TCC: automatic mode and on-demand mode. If both modes are activated,
automatic mode takes precedence.
Intel Thermal Monitor 1 (TM1) mode is selected by writing values to the MSRs of the
processor. After automatic mode is enabled, the TCC will activate only when the
internal die temperature reaches the maximum allowed value for operation.
processor. After automatic mode is enabled, the TCC will activate only when the
internal die temperature reaches the maximum allowed value for operation.