250686-007 Datasheet, PDF (85/97 Pages) Intel Corporation – Mobile Intel Pentium4 Processor-M

Pin Listing and Signal Definitions
Table 37. Signal Description (Page 5 of 8)
Name
Type
Description
HIT#
HITM#
IERR#
IGNNE#
INIT#
ITPCLKOUT
[1:0]
ITP_CLK[1:0]
LINT[1:0]
LOCK#
Input/
Output
Input/
Output
HIT# (Snoop Hit) and HITM# (Hit Modified) convey transaction snoop operation
results. Any system bus 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.
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 system bus. This transaction may optionally be converted to an external
error signal (e.g., NMI) by system core logic. The processor will keep IERR#
asserted until the assertion of RESET#.
This signal does not have on-die termination and must be terminated on the
system board.
Input
IGNNE# (Ignore Numeric Error) is asserted to force the processor to ignore a
numeric error and continue to execute noncontrol floating-point instructions. If
IGNNE# is deasserted, the processor generates an exception on a noncontrol
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.
Input
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#
assertion. INIT# is an asynchronous signal and must connect the appropriate pins
of all processor system bus agents.
If INIT# is sampled active on the active to inactive transition of RESET#, then the
processor executes its Built-in Self-Test (BIST).
Output
ITPCLKOUT[1:0] is an uncompensated differential clock output that is a delayed
copy of the BCLK[1:0], which is an input to the processor. This clock output can be
used as the differential clock into the ITP port that is designed onto the
motherboard. If ITPCLKOUT[1:0] outputs are not used, they must be terminated
properly. Refer to Section 2.5 for additional details and termination requirements.
Input
ITP_CLK[1:0] are copies of BCLK that are used only in processor systems where
no debug port is implemented on the system board. ITP_CLK[1:0] are used as
BCLK[1:0] references for a debug port implemented on an interposer. If a debug
port is implemented in the system, ITP_CLK[1:0] are no connects in the system.
These are not processor signals.
Input
LINT[1:0] (Local APIC Interrupt) must connect the appropriate pins of all APIC Bus
agents. When the APIC is disabled, the LINT0 signal becomes INTR, a maskable
interrupt request signal, and LINT1 becomes NMI, a nonmaskable interrupt. INTR
and NMI are backward compatible with the signals of those names on the Pentium
processor. Both signals are asynchronous.
Both of these signals must be software configured via BIOS programming of the
APIC register space to be used either as NMI/INTR or LINT[1:0]. Because the APIC
is enabled by default after Reset, operation of these pins as LINT[1:0] is the default
configuration.
Input/
Output
LOCK# indicates to the system that a transaction must occur atomically. This signal
must connect the appropriate pins of all processor system bus agents. For a locked
sequence of transactions, LOCK# is asserted from the beginning of the first
transaction to the end of the last transaction.
When the priority agent asserts BPRI# to arbitrate for ownership of the processor
system bus, it will wait until it observes LOCK# deasserted. This enables symmetric
agents to retain ownership of the processor system bus throughout the bus locked
operation and ensure the atomicity of lock.
Mobile Intel^ Pentium^ 4 Processor-M Datasheet
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