Intel BX80571E5300 - Pentium 2.6 GHz Processor, Datasheet

Page: 66 / 100

Land Listing and Signal Descriptions
66 Datasheet
D[63:0]#
Input/
Output
D[63:0]# (Data) are the data signals. These signals provide a 64-
bit data path between the processor FSB agents, and must connect
the appropriate pins/lands on all such agents. The data driver
asserts DRDY# to indicate a valid data transfer.
D[63:0]# are quad-pumped signals and will, thus, be driven four
times in a common clock period. D[63:0]# are latched off the
falling edge of both DSTBP[3:0]# and DSTBN[3:0]#. Each group of
16 data signals correspond to a pair of one DSTBP# and one
DSTBN#. The following table shows the grouping of data signals to
data strobes and DBI#.
Furthermore, the DBI# signals determine the polarity of the data
signals. Each group of 16 data signals corresponds to one DBI#
signal. When the DBI# signal is active, the corresponding data
group is inverted and therefore sampled active high.
DBI[3:0]#
Input/
Output
DBI[3:0]# (Data Bus Inversion) are source synchronous and
indicate the polarity of the D[63:0]# signals.The DBI[3:0]# signals
are activated when the data on the data bus is inverted. If more
than half the data bits, within a 16-bit group, would have been
asserted electrically low, the bus agent may invert the data bus
signals for that particular sub-phase for that 16-bit group.
DBR# Output
DBR# (Debug Reset) is used only in processor systems where no
debug port is implemented on the system board. DBR# is used by a
debug port interposer so that an in-target probe can drive system
reset. If a debug port is implemented in the system, DBR# is a no
connect in the system. DBR# is not a processor signal.
DBSY#
Input/
Output
DBSY# (Data Bus Busy) is asserted by the agent responsible for
driving data on the processor FSB to indicate that the data bus is in
use. The data bus is released after DBSY# is de-asserted. This
signal must connect the appropriate pins/lands on all processor FSB
agents.
Table 24. Signal Description (Sheet 3 of 10)
Name Type Description
Quad-Pumped Signal Groups
Data Group DSTBN#/DSTBP# DBI#
D[15:0]# 0 0
D[31:16]# 1 1
D[47:32]# 2 2
D[63:48]# 3 3
DBI[3:0] Assignment To Data Bus
Bus Signal Data Bus Signals
DBI3# D[63:48]#
DBI2# D[47:32]#
DBI1# D[31:16]#
DBI0# D[15:0]#