Техническая Спецификация для Intel Pentium D 830 HH80551PG0802MN

15

This chapter describes the electrical characteristics of the processor interfaces and signals. DC 
electrical characteristics are provided.

The Intel

®

 Pentium

®

 D processor has 226 VCC (power) and 273 VSS (ground) inputs for on-chip 

power distribution. All VCC lands must be connected to the processor power plane, while all VSS 
lands must be connected to the system ground plane. The processor VCC lands must be supplied 
with the voltage determined by the processor Voltage IDentification (VID) lands. 

The Pentium D processor has 24 signals that are denoted as VTT that provide termination for the 
front side bus and power to the I/O buffers. A separate supply must be implemented for these lands, 
that meets the V

TT

 specifications outlined in 

Due to its large number of transistors and high internal clock speeds, the processor is capable of 
generating large current swings between low and full power states. This may cause voltages on 
power planes to sag below their minimum values if bulk decoupling is not adequate. Larger bulk 
storage (C

BULK

), such as electrolytic or aluminum-polymer capacitors, supply current during 

longer lasting changes in current demand by the component, such as coming out of an idle 
condition. Similarly, they act as a storage well for current when entering an idle condition from a 
running condition. The motherboard must be designed to ensure that the voltage provided to the 
processor remains within the specifications listed in 

. Failure to do so can result in timing 

violations or reduced lifetime of the component. For further information and design guidelines, 
refer to the Voltage Regulator Down (VRD) 10.1 Design Guide For Desktop LGA775 Socket.

V

CC

 regulator solutions need to provide sufficient decoupling capacitance to satisfy the processor 

voltage specifications. This includes bulk capacitance with low effective series resistance (ESR) to 
keep the voltage rail within specifications during large swings in load current. In addition, ceramic 
decoupling capacitors are required to filter high frequency content generated by the front side bus 
and processor activity. Consult the Voltage Regulator Down (VRD) 10.1 Design Guide For 
Desktop LGA775 Socket for further information.

Decoupling must be provided on the motherboard. Decoupling solutions must be sized to meet the 
expected load. To insure compliance with the specifications, various factors associated with the 
power delivery solution must be considered including regulator type, power plane and trace sizing, 
and component placement. A conservative decoupling solution would consist of a combination of 
low ESR bulk capacitors and high frequency ceramic capacitors.