Datasheet

Datasheet 63
Package Mechanical Specifications and Pin Information
PROCHOT#
Input/
Output
As an output, PROCHOT# (Processor Hot) will go active when the
processor temperature monitoring sensor detects that the
processor has reached its maximum safe operating temperature.
This indicates that the processor Thermal Control Circuit (TCC) has
been activated, if enabled. As an input, assertion of PROCHOT# by
the system will activate the TCC, if enabled. The TCC will remain
active until the system deasserts PROCHOT#.
By default PROCHOT# is configured as an output. The processor
must be enabled via the BIOS for PROCHOT# to be configured as
bidirectional.
Refer to the appropriate platform design guide for termination
requirements.
This signal may require voltage translation on the motherboard.
PSI# Output
Processor Power Status Indicator signal. This signal is asserted
when the processor is both in the normal state (HFM to LFM) and in
lower power states (Deep Sleep and Deeper Sleep).
PWRGOOD Input
PWRGOOD (Power Good) is a processor input. The processor
requires this signal to be a clean indication that the clocks and
power supplies are stable and within their specifications. ‘Clean’
implies that the signal remains low (capable of sinking leakage
current), without glitches, from the time that the power supplies
are turned on until they come within specification. The signal must
then transition monotonically to a high state. Rise time and
monotonicity requirements are shown in Table 29. Figure 21
illustrates the relationship of PWRGOOD to the RESET# signal.
PWRGOOD can be driven inactive at any time, but clocks and
power must again be stable before a subsequent rising edge of
PWRGOOD. It must also meet the minimum pulse width
specification in Table 29, and be followed by a 2 ms (minimum)
RESET# pulse.
The PWRGOOD signal must be supplied to the processor; it is used
to protect internal circuits against voltage sequencing issues. It
should be driven high throughout boundary scan operation.
REQ[4:0]#
Input/
Output
REQ[4:0]# (Request Command) must connect the appropriate pins
of both FSB agents. They are asserted by the current bus owner to
define the currently active transaction type. These signals are
source synchronous to ADSTB[0]#.
RESET# Input
Asserting the RESET# signal resets the processor to a known state
and invalidates its internal caches without writing back any of their
contents. For a power-on Reset, RESET# must stay active for at
least two milliseconds after V
CC
and BCLK have reached their
proper specifications. On observing active RESET#, both FSB
agents will deassert their outputs within two clocks. All processor
straps must be valid within the specified setup time before RESET#
is deasserted.
Refer to the appropriate platform design guide for termination
requirements and implementation details. There is a 55 Ω
(nominal) on die pull-up resistor on this signal.
RS[2:0]# Input
RS[2:0]# (Response Status) are driven by the response agent (the
agent responsible for completion of the current transaction), and
must connect the appropriate pins of both FSB agents.
Table 14. Signal Description (Sheet 7 of 9)
Name Type Description