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Table 25.
Signal Description (Sheet 5 of 10)
Name
FERR#/PBE#
GTLREF[1:0]
HIT#
HITM#
IERR#
IGNNE#
INIT#
68
Type
FERR#/PBE# (floating point error/pending break event) is a
multiplexed signal and its meaning is qualified by STPCLK#. When
STPCLK# is not asserted, FERR#/PBE# indicates a floating-point
error and will be asserted when the processor detects an unmasked
floating-point error. When STPCLK# is not asserted, FERR#/PBE# is
similar to the ERROR# signal on the Intel 387 coprocessor, and is
included for compatibility with systems using MS-DOS*-type
floating-point error reporting. When STPCLK# is asserted, an
Output
assertion of FERR#/PBE# indicates that the processor has a
pending break event waiting for service. The assertion of FERR#/
PBE# indicates that the processor should be returned to the Normal
state. For additional information on the pending break event
functionality including the identification of support of the feature
and enable/disable information, see volume 3 of the Intel
Architecture Software Developer's Manual and the Intel Processor
Identification and the CPUID Instruction application note.
GTLREF[1:0] determine the signal reference level for GTL+ input
Input
signals. GTLREF is used by the GTL+ receivers to determine if a
signal is a logical 0 or logical 1.
Input/
HIT# (Snoop Hit) and HITM# (Hit Modified) convey transaction
Output
snoop operation results. Any FSB agent may assert both HIT# and
HITM# together to indicate that it requires a snoop stall, which can
Input/
be continued by reasserting HIT# and HITM# together.
Output
IERR# (Internal Error) is asserted by a processor as the result of
an internal error. Assertion of IERR# is usually accompanied by a
SHUTDOWN transaction on the processor FSB. This transaction
may optionally be converted to an external error signal (such as,
Output
NMI) by system core logic. The processor keeps IERR# asserted
until the assertion of RESET#.
This signal does not have on-die termination. See
termination requirements.
IGNNE# (Ignore Numeric Error) is asserted to the processor to
ignore a numeric error and continue to execute noncontrol floating-
point instructions. If IGNNE# is de-asserted, the processor
generates an exception on a noncontrol floating-point instruction if
a previous floating-point instruction caused an error. IGNNE# has
Input
no effect when the NE bit in control register 0 (CR0) is set.
IGNNE# is an asynchronous signal. However, to ensure recognition
of this signal following an Input/Output write instruction, it must be
valid along with the TRDY# assertion of the corresponding Input/
Output write bus transaction.
INIT# (Initialization), when asserted, resets integer registers inside
the processor without affecting its internal caches or floating-point
registers. The processor then begins execution at the power-on
reset vector configured during power-on configuration. The
processor continues to handle snoop requests during INIT#
Input
assertion. INIT# is an asynchronous signal and must connect the
appropriate pins/lands of all processor FSB agents.
If INIT# is sampled active on the active to inactive transition of
RESET#, then the processor executes its Built-in Self-Test (BIST).
Land Listing and Signal Descriptions
Description
Section 2.6.2
for
Datasheet
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