104 Datasheet
Signals Reference
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.
A.1.60 TCK (I)
The Test Clock (TCK) signal provides the clock input for the IEEE 1149.1 compliant TAP.
A.1.61 TDI (I)
The Test Data In (TDI) signal transfers serial test data into the Itanium 2 processor. TDI provides
the serial input needed for IEEE 1149.1 compliant TAP.
A.1.62 TDO (O)
The Test Data Out (TDO) signal transfers serial test data out from the Itanium 2 processor. TDO
provides the serial output needed for IEEE 1149.1 compliant TAP.
A.1.63 THRMTRIP# (O)
The Thermal Trip (THRMTRIP#) signal protects the Itanium 2 processor from catastrophic
overheating by use of an internal thermal sensor. This sensor is set well above the normal operating
temperature to ensure that there are no false trips. Data will be lost if the processor goes into
thermal trip (signaled to the system by the assertion of the THRMTRIP# signal). Once
THRMTRIP# is asserted, the platform must assert RESET# to protect the physical integrity of the
processor.
Table A-11. STBp[7:0]# and STBn[7:0]# Associations
Strobe Bits Data Bits ECC Bits
STBp[7]#, STBn[7]# D[127:112]# DEP[15:14]#
STBp[6]#, STBn[6]# D[111:96]# DEP[13:12]#
STBp[5]#, STBn[5]# D[95:80]# DEP[11:10]#
STBp[4]#, STBn[4]# D[79:64]# DEP[9:8]#
STBp[3]#, STBn[3]# D[63:48]# DEP[7:6]#
STBp[2]#, STBn[2]# D[47:32]# DEP[5:4]#
STBp[1]#, STBn[1]# D[31:16]# DEP[3:2]#
STBp[0]#, STBn[0]# D[15:0]# DEP[1:0]#