Vol 1

Intel® Xeon® Product 2800/4800/8800 v2 Product Family 73
Datasheet Volume One, February 2014
Electrical Specifications
6.1.9.3.1 SVID Commands
The Intel® Xeon® E7 v2 processor provides the ability to operate while transitioning to
a new VID setting and its associated processor voltage rail (V
CC and
V
SA
). This is
represented by a DC shift. It should be noted that a low-to-high or high-to-low voltage
state change may result in as many VID transitions as necessary to reach the target
voltage. Transitions above the maximum specified VID are not supported. The
processor supports the following VR commands:
• SetVID_fast (20 mV/us),
• SetVID_slow (5 mV/us), and
• Slew Rate Decay (downward voltage only and it’s a function of the output
capacitance’s time constant) commands. Table 6-3 and Table 6-26 includes SVID
step sizes and DC shift ranges. Minimum and maximum voltages must be
maintained as shown in Table 6-12.
The VRM or EVRD utilized must be capable of regulating its output to the value defined
by the new VID.
Power source characteristics must be guaranteed to be stable whenever the supply to
the voltage regulator is stable.
6.1.9.3.2 SetVID Fast Command
The SetVID-fast command contains the target VID in the payload byte. The range of
voltage is defined in the VID table. The VR should ramp to the new VID setting with a
fast slew rate as defined in the slew rate data register. Typically 10 to 20 mV/uS
depending on platform and the amount of decoupling capacitance.
The SetVID-fast command is preemptive, the VR interrupts its current processes and
moves to the new VID. The SetVID-fast command operates on 1 VR address at a time.
This command is used in the processor for package C6 fast exit.
6.1.9.3.3 SetVID Slow
The SetVID-slow command contains the target VID in the payload byte. The range of
voltage is defined in the VID table. The VR should ramp to the new VID setting with a
“slow” slew rate as defined in the slow slew rate data register. Typically the
SetVID_Slow is 4x slower than the SetVID_fast slew rate.
The SetVID-slow command is preemptive, the VR interrupts its current processes and
moves to the new VID. This is the instruction used for normal P-state voltage change.
This command is used in the processor for the Intel Enhanced SpeedStep Technology
transitions.
6.1.9.3.4 SetVID Decay
The SetVID-Decay command is the slowest of the DVID transitions. It is normally used
for VID down transitions. The VR does not control the slew rate, the output voltage
declines with the output load current only.
The SetVID- Decay command is preemptive, the VR interrupts its current processes
and moves to the new VID. This command is used in the processor for package C6
entry, allowing capacitor discharge by the leakage, thus saving energy.This command is
normally used in VID down direction in the processor package C6 entry.