Intel Itanium 2 Processor Computer Hardware User Manual


 
98 Datasheet
Signals Reference
The Deferred Reply agent transmits the DID[9:0]# (Ab[25:16]#) signals received during the
original transaction on the Aa[25:16]# signals during the Deferred Reply transaction. This process
enables the original requesting agent to make an identifier match with the original request that is
awaiting completion.
A.1.27 DPS# (I/O)
The Deferred Phase Enable (DPS#) signal is driven to the bus on the second clock of the Request
Phase on the Ab[3]# pin. DPS# is asserted if a requesting agent supports transaction completion
using the Deferred Phase. A requesting agent that supports the Deferred Phase will always assert
DPS#. A requesting agent that does not support the Deferred Phase will always deassert DPS#.
A.1.28 DRDY# (I/O)
The Data Ready (DRDY#) signal is asserted by the data driver on each data transfer, indicating
valid data on the data bus. In a multi-cycle data transfer, DRDY# can be deasserted to insert
idle clocks.
DRDY# is replicated three times to enable partitioning of data paths in the system agents. This
copy of the Data Ready signal (DRDY#) is an input as well as an output.
A.1.29 DRDY_C1# (O)
DRDY# is a copy of the Data Ready signal. This copy of the Data Phase data-ready signal
(DRDY_C1#) is an output only.
A.1.30 DRDY_C2# (O)
DRDY# is a copy of the Data Ready signal. This copy of the Data Phase data-ready signal
(DRDY_C2#) is an output only.
A.1.31 DSZ[1:0]# (I/O)
The Data Size (DSZ[1:0]#) signals are transferred on REQb[4:3]# signals in the second clock of
the Request Phase by the requesting agent. The DSZ[1:0]# signals define the data transfer
capability of the requesting agent. For the Itanium 2 processor, DSZ# = 01, always.
A.1.32 EXF[4:0]# (I/O)
The Extended Function (EXF[4:0]#) signals are transferred on the A[7:3]# pins by the requesting
agent during the second clock of the Request Phase. The signals specify any special functional
requirement associated with the transaction based on the requestor mode or capability. The signals
are defined in Table A-8.