Intel E5-2448L CM8062007187409 User Manual

Intel® Xeon® Processor E5-1600/E5-2600/E5-4600 Product Families

157

Datasheet Volume One

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.

The processor provides the ability to operate while transitioning to a new VID setting 
and its associated processor voltage rails (V

CC, 

V

SA

, and V

CCD

). 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/µs for V

CC

,10 mV/µs for V

SA

/V

CCD

), 

• SetVID_slow (5 mV/µs for V

CC

, 2.5 mV/µs for V

SA

/V

CCD

), and 

• Slew Rate Decay (downward voltage only and it’s a function of the output 

capacitance’s time constant) commands. 

 includes SVID 

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.

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.

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.

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.