Electrical Specifications
156 Intel® Xeon® Processor E5-1600/E5-2600/E5-4600 Product Families
Datasheet Volume One
7.1.9.2 Decoupling Guidelines
Due to its large number of transistors and high internal clock speeds, the processor is
capable of generating large current swings between low and full power states. This may
cause voltages on power planes to sag below their minimum values if bulk decoupling is
not adequate. Large electrolytic bulk capacitors (CBULK), help maintain the output
voltage during current transients, for example coming out of an idle condition. Care
must be taken in the baseboard design to ensure that the voltages provided to the
processor remain within the specifications listed in Tabl e 7-11 . Failure to do so can
result in timing violations or reduced lifetime of the processor. For further information,
refer to the appropriate Platform Design Guide (PDG).
7.1.9.3 Voltage Identification (VID)
The Voltage Identification (VID) specification for the VCC, VSA, VCCD voltage are defined
by the VR12/IMVP7 Pulse Width Modulation Specification. The reference voltage or the
VID setting is set via the SVID communication bus between the processor and the
voltage regulator controller chip. The VID settings are the nominal voltages to be
delivered to the processor's VCC, VSA, VCCD lands. Tabl e 7-3 specifies the reference
voltage level corresponding to the VID value transmitted over serial VID. The VID codes
will change due to temperature and/or current load changes in order to minimize the
power and to maximize the performance of the part. The specifications are set so that a
voltage regulator can operate with all supported frequencies.
Individual processor VID values may be calibrated during manufacturing such that two
processor units with the same core frequency may have different default VID settings.
The processor uses voltage identification signals to support automatic selection of VCC,
VSA, and VCCD power supply voltages. If the processor socket is empty (SKTOCC_N
high), or a “not supported” response is received from the SVID bus, then the voltage
regulation circuit cannot supply the voltage that is requested, the voltage regulator
must disable itself or not power on. Vout MAX register (30h) is programmed by the
processor to set the maximum supported VID code and if the programmed VID code is
Table 7-1. Power and Ground Lands
Power and
Ground Lands Number of
Lands Comments
VCC 208 Each VCC land must be supplied with the voltage determined by the
SVID Bus signals. Table 7 -3 Defines the voltage level associated with
each core SVID pattern.Table 7 -11, Figure 7-2, and Figure 7-5
represent VCC static and transient limits. VCC has a VBOOT setting of
0.0V.
VCCPLL 3Each V
CCPLL land is connected to a 1.80 V supply, power the Phase
Lock Loop (PLL) clock generation circuitry. An on-die PLL filter
solution is implemented within the processor.
VCCD_01
VCCD_23
51 Each VCCD land is connected to a switchable 1.50 V and 1.35 V supply,
provide power to the processor DDR3 interface. These supplies also
power the DDR3 memory subsystem. VCCD is also controlled by the
SVID Bus. VCCD is the generic term for VCCD_01, VCCD_23.
VTTA 14 VTTA lands must be supplied by a fixed 1.05V supply.
VTTD 19 VTTD lands must be supplied by a fixed 1.05V supply.
VSA 25 Each VSA land must be supplied with the voltage determined by the
SVID Bus signals, typically set at 0.965V. VSA has a VBOOT setting of
0.9V.
VSS 548 Ground