Intel BX80619I73960X, Datasheet

Page: 53 / 120

Datasheet, Volume 1 53
Electrical Specifications
7.1.8.3.2 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, 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.
7.1.8.3.3 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. 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.
7.1.8.3.4 SetVID Decay
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.
7.1.8.3.5 SVID Power State Functions – SetPS
The processor has three power state functions and these will be set seamlessly using
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:
• PS(00h): Represents full power or active mode
• PS(01h): Represents a light load 5 A to 20 A
• PS(02h): Represents a very light load <5 A
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(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.
The SetPS command sends a byte that is encoded as to what power state the VR
should transition to.