Datasheet

Electrical Specifications
64 Intel® Xeon® Processor 3400 Series Datasheet, Volume 1
7.5 Reserved or Unused Signals
The following are the general types of reserved (RSVD) signals and connection
guidelines:
• RSVD — these signals should not be connected
• RSVD_TP — these signals should be routed to a test point
• RSVD_NCTF — these signals are non-critical to function and may be left un-
connected
Arbitrary connection of these signals to V
CC
, V
TT
, V
DDQ
, V
CCPLL
, V
SS
, or to any other
signal (including each other) may result in component malfunction or incompatibility
with future processors. See Chapter 8 for a land listing of the processor and the
location of all reserved signals.
For reliable operation, always connect unused inputs or bi-directional signals to an
appropriate signal level. Unused active high inputs should be connected through a
resistor to ground (V
SS
). Unused outputs may be left unconnected; however, this may
interfere with some Test Access Port (TAP) functions, complicate debug probing, and
prevent boundary scan testing. A resistor must be used when tying bi-directional
signals to power or ground. When tying any signal to power or ground, a resistor will
also allow for system testability. For details, see Table 7-9.
7.6 Signal Groups
Signals are grouped by buffer type and similar characteristics as listed in Table 7-3. The
buffer type indicates which signaling technology and specifications apply to the signals.
All the differential signals, and selected DDR3 and Control Sideband signals have On-
Die Termination (ODT) resistors. There are some signals that do not have ODT and
need to be terminated on the board.