Processor—Electrical Specifications

7.0Electrical Specifications

This chapter provides the processor electrical specifications including integrated voltage regulator (VR), VCC Voltage Identification (VID), reserved and unused signals, signal groups, Test Access Points (TAP), and DC specifications.

7.1Integrated Voltage Regulator

A new feature to the processor is the integration of platform voltage regulators into the processor. Due to this integration, the processor has one main voltage rail (VCC) and a voltage rail for the memory interface (VDDQ) , compared to six voltage rails on previous processors. The VCC voltage rail will supply the integrated voltage regulators which in turn will regulate to the appropriate voltages for the cores, cache, system agent, and graphics. This integration allows the processor to better control on-die voltages to optimize between performance and power savings. The processor VCC rail will remain a VID-based voltage with a loadline similar to the core voltage rail (also called VCC) in previous processors.

7.2Power and Ground Lands

The processor has VCC, VDDQ, and VSS (ground) lands for on-chip power distribution. All power lands must be connected to their respective processor power planes, while all VSS lands must be connected to the system ground plane. Use of multiple power and ground planes is recommended to reduce I*R drop. The VCC lands must be supplied with the voltage determined by the processor Serial Voltage IDentification (SVID) interface. Table 38 on page 87 specifies the voltage level for the various VIDs.

7.3VCC Voltage Identification (VID)

The processor uses three signals for the serial voltage identification interface to support automatic selection of voltages. The following table specifies the voltage level corresponding to the 8-bit VID value transmitted over serial VID. A ‘1’ in this table refers to a high voltage level and a ‘0’ refers to a low voltage level. If the voltage regulation circuit cannot supply the voltage that is requested, the voltage regulator must disable itself. VID signals are CMOS push/pull drivers. See Table 46 on page 98 for the DC specifications for these signals. The VID codes will change due to temperature and/or current load changes in order to minimize the power of the part. A voltage range is provided in Voltage and Current Specifications on page 94. The specifications are set so that one voltage regulator can operate with all supported frequencies.

Individual processor VID values may be set during manufacturing so that two devices at the same core frequency may have different default VID settings. This is shown in the VID range values in Voltage and Current Specifications on page 94. The processor provides the ability to operate while transitioning to an adjacent VID and its associated voltage. This will represent a DC shift in the loadline.

Intel® Xeon® Processor E3-1200 v3 Product Family

 

Datasheet – Volume 1 of 2

June 2013

86

Order No.: 328907-001