Land Listing and Signal Descriptions
Table 25.
Signal Description (Sheet 1 of 9)
Name
Type
Description
VID[5:0] (Voltage ID) signals are used to support automatic
selection of power supply voltages (VCC). Refer to the Voltage
Regulator-Down (VRD) 10.1 Design Guide for Desktop Socket 775
for more information. The voltage supply for these signals must be
valid before the VR can supply VCC to the processor. Conversely,
the VR output must be disabled until the voltage supply for the VID
signals becomes valid. The VID signals are needed to support the
processor voltage specification variations. See Table 2 for
definitions of these signals. The VR must supply the voltage that is
requested by the signals, or disable itself.
VID[5:0]
Output
VSS are the ground pins for the processor and should be connected
to the system ground plane.
VSS
Input
Input
VSSA
VSSA is the isolated ground for internal PLLs.
VSS_SENSE is an isolated low impedance connection to processor
VSS_SENSE
Output core VSS. It can be used to sense or measure ground near the
silicon with little noise.
This land is provided as a voltage regulator feedback sense point
VSS_MB_
REGULATION
for VSS. It is connected internally in the processor package to the
sense point land V27 as described in the Voltage Regulator-Down
Output
(VRD) 10.1 Design Guide for Desktop Socket 775.
VTT
Miscellaneous voltage supply.
VTT_OUT_LEFT
The VTT_OUT_LEFT and VTT_OUT_RIGHT signals are included to
Output provide a voltage supply for some signals that require termination
to VTT on the motherboard.
VTT_OUT_RIGHT
VTT_SEL
The VTT_SEL signal is used to select the correct VTT voltage level
Output for the processor. This land is connected internally in the package
to VTT.
The processor requires this input to determine that the VTT voltages
are stable and within specification.
VTTPWRGD
Input
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Datasheet
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INTEL [ INTEL ]
