Electrical Specifications
80 Datasheet, Volume 1
7.5 System Agent (SA) VCC VID
The VCCSA is configured by the processor output land VCCSA_VID. VCCSA_VID output
default logic state is low for 2nd generation and 3rd generation Desktop Core
processors, and configures VCCSA to 0.925 V.
7.6 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 must be routed to a test point. Failure to route these
signal to test points will restrict Intel’s ability to assist in platform debug.
RSVD_NCTF – these signals are non-critical to function and may be left un-
connected.
Arbitrary connection of these signals to VCC, VCCIO, VDDQ, VCCPLL, VCCSA, VAXG, VSS, 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 (VSS). Unused outputs maybe 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 7-8.
7.7 Signal Groups
Signals are grouped by buffer type and similar characteristics as listed in Table 7-2. 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.