24
Datasheet
Electrical Specifications
NOTES:
1. Signals that do not have RTT, nor are actively driven to their high voltage level.
2. The termination for these signals is not RTT. The OPTIMIZED/COMPAT# and BOOT_SELECT pins have a
500 - 5000
pull-up to VTT.
NOTES:
1. These signals also have hysteresis added to the reference voltage. See
Table 2-13 for more information.
2.7
GTL+ Asynchronous and AGTL+ Asynchronous
Signals
The 64-bit Intel Xeon processor with 2 MB L2 cache does not use CMOS voltage levels on any
signals that connect to the processor silicon. As a result, input signals such as A20M#,
FORCEPR#, IGNNE#, INIT#, LINT0/INTR, LINT1/NMI, SMI#, SLP#, and STPCLK# utilize
GTL input buffers. Legacy output THERMTRIP# utilizes a GTL+ output buffers. All of these
Asynchronous GTL+ signals follow the same DC requirements as GTL+ signals, however the
outputs are not driven high (during the logical 0-to-1 transition) by the processor. FERR#/PBE#,
IERR#, and IGNNE# have now been defined as AGTL+ asynchrnous signals as they include an
active p-MOS device. GTL+ asynchronous and AGTL+ asynchronous signals do not have setup or
hold time specifications in relation to BCLK[1:0]. However, all of the GTL+ asynchronous and
AGTL+ asynchronous signals are required to be asserted/deasserted for at least six BCLKs in order
for the processor to recognize them. See
Table 2-14 for the DC specifications for the asynchronous
GTL+ signal groups.
2.8
Test Access Port (TAP) Connection
Due to the voltage levels supported by other components in the Test Access Port (TAP) logic, it is
recommended that the processor(s) be first in the TAP chain and followed by any other components
within the system. A translation buffer should be used to connect to the rest of the chain unless one
Table 2-5. Signal Description Table
Signals with RTT
A[35:3]#, ADS#, ADSTB[1:0]#, AP[1:0]#, BINIT#, BNR#, BOOT_SELECT2, BPRI#, D[63:0]#, DBI[3:0]#,
DBSY#, DEFER#, DP[3:0]#, DRDY#, DSTBN[3:0]#, DSTBP[3:0]#, FORCEPR#, HIT#, HITM#, LOCK#,
MCERR#, OPTIMIZED/COMPAT#2, REQ[4:0]#, RS[2:0]#, RSP#, SLEW_CTRL, TEST_BUS, TRDY#
Signals with RL
BINIT#, BNR#, HIT#, HITM#, MCERR#
Table 2-6. Signal Reference Voltages
GTLREF
0.5 * VTT
A20M#, A[35:3]#, ADS#, ADSTB[1:0]#, AP[1:0]#,
BINIT#, BNR#, BPM[5:0]#, BPRI#, BR[3:0]#,
D[63:0]#, DBI[3:0]#, DBSY#, DEFER#, DP[3:0]#,
DRDY#, DSTBN[3:0]#, DSTBP[3:0]#, FORCEPR#,
HIT#, HITM#, IGNNE#, INIT#, LINT0/INTR, LINT1/
NMI, LOCK#, MCERR#, ODTEN, RESET#,
REQ[4:0]#, RS[2:0]#, RSP#, SLEW_CTRL, SLP#,
SMI#, STPCLK#, TRDY#
BOOT_SELECT, OPTIMIZED/COMPAT#, PWRGOOD1,
TCK1, TDI1, TMS1, TRST#1, VIDPWRGD