Datasheet

Signal Definitions
70
DRDY# I/O DRDY# (Data Ready) is asserted by the data driver on each data
transfer, indicating valid data on the data bus. In a multi-common
clock data transfer, DRDY# may be deasserted to insert idle clocks.
This signal must connect the appropriate pins of all processor FSB
agents.
3
DSTBN[3:0]# I/O Data strobe used to latch in D[63:0]#. 3
DSTBP[3:0]# I/O Data strobe used to latch in D[63:0]#. 3
FERR#/PBE# O 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 Intel387 coprocessor, and is
included for compatibility with systems using MS-DOS*-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. For additional
information on the pending break event functionality, including the
identification of support of the feature and enable/disable
information, refer to Vol. 3 of the Intel
®
64 and IA-32 Architectures
Software Developer’s Manual and the Intel Processor Identification
and the CPUID Instruction application note.
2
FORCEPR# I The FORCEPR# (force power reduction) input can be used by the
platform to cause the Dual-Core Intel® Xeon® Processor 5200 Series
to activate the Thermal Control Circuit (TCC).
GTLREF_ADD I GTLREF_ADD determines the signal reference level for AGTL+
address and common clock input lands. GTLREF_ADD is used by the
AGTL+ receivers to determine if a signal is a logical 0 or a logical 1.
Please refer to Table 2-18 and the appropriate platform design
guidelines for additional details.
GTLREF_DATA I GTLREF_DATA determines the signal reference level for AGTL+ data
input lands. GTLREF_DATA is used by the AGTL+ receivers to
determine if a signal is a logical 0 or a logical 1. Please refer to
Table 2-18 and the appropriate platform design guidelines for
additional details.
HIT#
HITM#
I/O
I/O
HIT# (Snoop Hit) and HITM# (Hit Modified) convey transaction snoop
operation results. Any 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.
3
Table 5-1. Signal Definitions (Sheet 4 of 8)
Name Type Description Notes
Signals Associated Strobes
D[15:0]#, DBI0# DSTBN0#
D[31:16]#, DBI1# DSTBN1#
D[47:32]#, DBI2# DSTBN2#
D[63:48]#, DBI3# DSTBN3#
Signals Associated Strobes
D[15:0]#, DBI0# DSTBP0#
D[31:16]#, DBI1# DSTBP1#
D[47:32]#, DBI2# DSTBP2#
D[63:48]#, DBI3# DSTBP3#