Intel Xeon Processor E5-1600 Datasheet page 157

Electrical Specifications
higher than the VID supported by the VR, then VR will respond with a "not supported"
acknowledgement. See the VR12/IMVP7 Pulse Width Modulation Specification for
further details.
7.1.9.3.1 SVID Commands
The processor provides the ability to operate while transitioning to a new VID setting
and its associated processor voltage rails (V
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/µs for V
• SetVID_slow (5 mV/µs for V
• Slew Rate Decay (downward voltage only and it's a function of the output
capacitance's time constant) commands.
step sizes and DC shift ranges. Minimum and maximum voltages must be
maintained as shown in
The VRM or EVRD utilized must be capable of regulating its output to the value defined
by the new VID. The VR12/IMVP7 Pulse Width Modulation Specification contains further
details.
Power source characteristics must be guaranteed to be stable whenever the supply to
the voltage regulator is stable.
7.1.9.3.2 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/µs
depending on platform, voltage rail, 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 and entry.
7.1.9.3.3 SetVID Slow Command
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. The SetVID_Slow is 1/4
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.
7.1.9.3.4 SetVID-Decay Command
The SetVID-Decay command is the slowest of the DVID transitions. It is only 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, that is, the VR interrupts its current
processes and moves to the new VID.
Intel® Xeon® Processor E5-1600/E5-2600/E5-4600 Product Families
Datasheet Volume One
V , and V
CC, SA
,10 mV/µs for V
CC SA
, 2.5 mV/µs for V
CC
Table 7-3
Table 7-11.
). This is represented by a
CCD
/V ),
CCD
/V ), and
SA CCD
and Table 7-21 includes SVID
157