Datasheet

Package Mechanical Specifications and Pin Information
Datasheet 59
Signal Name Type Description
FERR#/PBE# O
FERR# (Floating-point Error) PBE# (Pending Break Event) is a
multiplexed signal and its meaning is qualified with STPCLK#.
When STPCLK# is not asserted, FERR#/PBE# indicates a floating
point when the processor detects an unmasked floating-point
error. FERR# is similar to the ERROR# signal on the Intel 387
coprocessor, and is included for compatibility with systems using
MSDOS*- type floating-point error reporting. When STPCLK# is
asserted, an 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. When FERR#/PBE# is asserted,
indicating a break event, it will remain asserted until STPCLK# is
de-asserted. Assertion of PREQ# when STPCLK# is active will
also cause an FERR# break event.
For additional information on the pending break event
functionality, including identification of support of the feature and
enable/disable information, refer to Volume 3 of the Intel® 64
and IA-32 Architectures Software Developer's Manuals and the
Intel® Processor Identification and CPUID Instruction Application
Note.
CMREF PWR
CMREF determines the signal reference level for CMOS input
pins. CMREF should be set at 1/2 V
CCP
. CMREF is used by the
CMOS receivers to determine if a signal is a logical 0 or logical 1.
If not using CMOS, then all CMREF and GTLREF should be
provided with 2/3 V
CCP
.
GTLREF PWR
GTLREF determines the signal reference level for AGTL+ input
pins. GTLREF should be set at 2/3 V
CCP
. GTLREF is used by the
AGTL+ receivers to determine if a signal is a logical 0 or logical
HIT#
HITM#
I/O
HIT# (Snoop Hit) and HITM# (Hit Modified) convey transaction
snoop operation results. Either FSB agent may assert both HIT#
and HITM# together to indicate that it requires a snoop stall,
which can be continued by reasserting HIT# and HITM#
together.
IERR# O
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 FSB. This transaction may
optionally be converted to an external error signal (for example,
NMI) by system core logic. The processor will keep IERR#
asserted until the assertion of RESET# or INIT#.
IGNNE# I
IGNNE# (Ignore Numeric Error) is asserted to force the
processor to ignore a numeric error and continue to execute non-
control floating-point instructions. If IGNNE# is de-asserted, the
processor generates an exception on a non-control floating-point
instruction if a previous floating-point instruction caused an
error. IGNNE# has 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.