Intel E5-4600 manual Svid Commands, SetVID Fast Command, SetVID Slow Command, SetVID-Decay Command

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.

7.1.9.3.1SVID Commands

The processor provides the ability to operate while transitioning to a new VID setting and its associated processor voltage rails (VCC, VSA, and VCCD). 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 VCC,10 mV/µs for VSA/VCCD),

•SetVID_slow (5 mV/µs for VCC, 2.5 mV/µs for VSA/VCCD), and

•Slew Rate Decay (downward voltage only and it’s a function of the output capacitance’s time constant) commands. Table 7-3and Table 7-21includes SVID step sizes and DC shift ranges. Minimum and maximum voltages must be maintained as shown in Table 7-11.

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.

7.1.9.3.2SetVID 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.

7.1.9.3.3SetVID 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.

7.1.9.3.4SetVID-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	157
Datasheet Volume One