Dual-Core Intel Itanium Processor 9000 Series Datasheet
103
Signals Reference
A.1.53
RS[2:0]# (I)
The Response Status (RS[2:0]#) signals are driven by the responding agent (the agent
responsible for completion of the transaction).
A.1.54
RSP# (I)
The Response Parity (RSP#) signal is driven by the responding agent (the agent
responsible for completion of the current transaction) during assertion of RS[2:0]#, the
signals for which RSP# provides parity protection.
A correct parity signal is high if an even number of covered signals are low and low if an
odd number of covered signals are low. During the Idle state of RS[2:0]#
(RS[2:0]#=000), RSP# is also high since it is not driven by any agent guaranteeing
correct parity.
A.1.55
SBSY# (I/O)
The Strobe Bus Busy (SBSY#) signal is driven by the agent transferring data when it
owns the strobe bus. SBSY# holds the strobe bus before the first DRDY# and between
DRDY# assertions for a multiple clock data transfer. SBSY# is deasserted before
DBSY# to allow the next data transfer agent to predrive the strobes before the data
bus is released.
SBSY# is replicated three times to enable partitioning of data paths in the system
agents. This copy of the Strobe Bus Busy signal (SBSY#) is an input as well as an
output.
A.1.56
SBSY_C1# (O)
SBSY# is a copy of the Strobe Bus Busy signal. This copy of the Strobe Bus Busy signal
(SBSY_C1#) is an output only.
A.1.57
SBSY_C2# (O)
SBSY# is a copy of the Strobe Bus Busy signal. This copy of the Strobe Bus Busy signal
(SBSY_C2#) is an output only.
A.1.58
SPLCK# (I/O)
The Split Lock (SPLCK#) signal is driven in the second clock of the Request Phase on
the Ab[6]# pin of the first transaction of a locked operation. It is driven to indicate that
the locked operation will consist of four locked transactions.
A.1.59
STBn[7:0]# and STBp[7:0]# (I/O)
STBp[7:0]# and STBn[7:0]# (and DRDY#) are used to transfer data at the 2x transfer
rate in lieu of BCLKp. They are driven by the data transfer agent with a tight skew
relationship with respect to its corresponding bus signals, and are used by the receiving
agent to capture valid data in its latches. This functions like an independent double
frequency clock constructed from a falling edge of either STBp[7:0]# or STBn[7:0]#.
The data is synchronized by DRDY#. Each strobe pair is associated with 16 data bus
signals and two ECC signals as shown in
Table A-11.