Intel E5-1428L CM8062001144000 Data Sheet

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.

The processor has three power state functions and these will be set seamlessly via the

SVID bus using the SetPS command. Based on the power state command, the SetPS

commands sends information to VR controller to configure the VR to improve

efficiency, especially at light loads. For example, typical power states are:
•

PS0(00h): Represents full power or active mode

•

PS1(01h): Represents a light load 5A to 20A

•

PS2(02h): Represents a very light load <5A

The VR may change its configuration to meet the processor's power needs with

greater efficiency. For example, it may reduce the number of active phases, transition

from CCM (Continuous Conduction Mode) to DCM (Discontinuous Conduction Mode)

mode, reduce the switching frequency or pulse skip, or change to asynchronous

regulation. For example, typical power states are 00h = run in normal mode; a

command of 01h = shed phases mode, and an 02h = pulse skip.

The VR may reduce the number of active phases from PS(00h) to PS(01h) or PS(00h)

to PS(02h) for example. There are multiple VR design schemes that can be used to

maintain a greater efficiency in these different power states, please work with your VR

controller suppliers for optimizations.

If a power state is not supported by the controller, the slave should acknowledge the

SetPS command and enter the lowest power state that is supported.

If the VR is in a low power state and receives a SetVID command moving the VID up

then the VR exits the low power state to normal mode (PS0) to move the voltage up

as fast as possible. The processor must re-issue low power state (PS1 or PS2)

command if it is in a low current condition at the new higher voltage. See the figure

below for VR power state transitions.

Intel

®

 Xeon

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 Processor E5-1600 and E5-2600 v3 Product Families, Volume 1 of 2, Electrical

September 2014

Datasheet

Order No.: 330783-001

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